Yet Another Zombie Defense HD Achievement Guide & Road Map

Yet Another Zombie Defense HD
Yet Another Zombie Defense HD Achievement Guide

Overview:
- Estimated achievement difficulty: 4/10 and luck dependent solo; 3/10 co-op [Achievement Difficulty Rating]
- Offline: 27 [1000]
- Online: 0
- Approximate amount of time to 1000

: 3-5 hours [Estimated Time to 100%]
- Minimum number of playthroughs needed: Multiple short runs in Defense mode, one Deathmatch game, and one Endless run
- Missable achievements: None [arcade style gameplay]
- Does difficulty affect achievements: No difficulty option
- Unobtainable/glitched achievements: None

Introduction:
Welcome to Yet Another Zombie Defense HD, a game that is, appropriately, yet another generic zombie defense game. It is extremely simple and minimalistic. The entire game consists of one "level," if you can call it that, which is just an open smallish area. The game alternates between day time, when you can safely build stuff and stock up on ammo and weapons, and night time, when you need to defend against zombies (as well as other creatures) in a twin stick style gameplay. You'll be amassing money to buy bigger and better weapons, buy and build barricades to protect you from enemies, etc. It's a simple game that won't require much effort to unlock all achievements, with the right strategy. Let's get started.

Abbreviated Walkthrough:
The three game modes below can be done in any order, but Endless Mode is the hardest, so I recommend doing it after you have experience with Defense Mode so you know what you're doing and what do expect. It's also worth noting that pretty much every achievement in Defense Mode only unlocks for the host, so don't even bother joining someone's game online for that mode. On the flip side, Endless Mode achievements are far, far easier with people online than solo, so I highly recommend looking for online lobbies in that mode.

Defense Mode:
Most of the achievements take place in this mode. As noted in the intro, this mode alternates between daytime where you can spend your money on weapons and barricades, and nighttime where you fight zombies with twin stick shooter gameplay. The game lulls you into a false sense of ease with how readily you can take out the first wave, but the strength of enemies quickly ramps up, so you'll need the right strategy to survive and get the achievements. Thankfully, there are some very simple and easy ways to do this. Feel free to work on achievements in any order you want and group them how you see fit, but here's how I progressed through this mode (and my game completion time is under three hours).

First playthrough:

Your goal here is to survive six nights without buying anything. This means it'll just be your pistol and whatever grenades you pick up from crates. You'll almost assuredly unlock Efficient usage (30G) on the first night, but don't worry if you don't, because you definitely will on your second run. Refer to Saving up (30G) for more detailed tips, but you shouldn't really have issues training enemies around while you shoot backwards at them. Save up grenades for Night 6 and use those grenades to help survive. Focus entirely on upgrading your Health Points with the stat upgrades you unlock, and you should be good.
After unlocking Saving up (30G), you'll be on Day 7 with a ton of money, since you didn't spend any. Buy the Chainsaw, which is really cheap, and that's all you're going to use for Night 7 to unlock Lumberjack (30G). For it (and for many other achievements), you're going to stand in any corner (I chose the bottom right corner) and just chainsaw everyone who comes your way. Don't throw any grenades!. Chainsaw only for that achievement. Grab any powerups that get dropped, and will the few Health Point upgrades you've been getting, you shouldn't have any problems surviving Night 7 with the Chainsaw to unlock Lumberjack (30G)
With that done, on Day 8, buy a ton of grenades (50 should be good), which you should have plenty of money for since the Chainsaw is really cheap and doesn't need ammo. Same strategy as before. Tuck into a corner and throw grenades nonstop to defeat enemies. Grab whatever they drop. Don't fire any weapons. You'll unlock Grenadier (30G) when the night ends
Next up on Day 9 is to spend all of your money on Landmines. You'll want a solid 80 or so, to be safe. Go around the open are and place landmines in a checkboard pattern to cover the maximum area. You'll want to place at least 80. Start the wave and do nothing with weapons or grenades. Just stand in the center of your mines and let enemies run into them and die. Toward the end you may need to kite enemies into them, but you'll unlock Watch your steps (30G) when done
You likely don't have much money left after buying so many landmines, so this is probably the end of this run. One thing you can mop up quick is buy a rocket launcher and let enemies group up then fire into them to try to unlock Demolition (30G). If you can't do it here, we'll do it later. That wraps up this run. You likely also got a bunch of point-related achievements. We'll finish those next

Second playthrough:
The goal here is to reach Night 16 to kill a reaper for Don't fear the reaper (100G) and to get 1,000,000 points along the way for Colonel (100G), which is practically unavoidable. We can also take care of Untouchable (50G) on this run. Refer to Untouchable (50G) for getting through the first 10 nights without taking damage, which isn't as hard as it sounds. Then, refer to Don't fear the reaper (100G) for a good strategy for surviving until Night 16 to kill a reaper. That strategy involves turrets, which will get you Come get some (30G) along the way. As noted, 1,000,000 points is essentially unavoidable by the time you get to Night 16. Getting Don't fear the reaper (100G), Colonel (100G), Untouchable (50G) and all the missing point-related achievements is it for this run. You can just let yourself die once you're done.

Third playthrough:
Here we're going to be getting Combat mastery (30G). It's actually pretty easy to do. Refer to the achievement solution for a guide on how to do it with ease. After those ten Nights, you should have a ton of money left since that strategy involves only the Chainsaw. This is the perfect opportunity (on Night 11) to get Arsonist (30G) with all the money you have built up. It needs to be done on at least Night 9 anyway, so this is the best time to do it rather than having to do another playthrough to that far into the game. Refer to Arsonist (30G) to take care of that.

Mop Up:
All that's left now are miscellaneous achievements. In particular are Not so fast (30G) for the Freeze Gun, Precise cut (30G) for the Laser, One shot, many kills (30G) for the Sniper, and potentially Demolition (30G) for the Rocket Launcher if you haven't done that yet. The exact same very reliable strategy can be used for all of those achievement. Refer to Precise cut (30G) for a guide on doing all of those achievements quickly and easily. The last two achievements not mentioned are Abandon all hope (30G) and Cheap and reliable (30G). The former is quick and easy at the start of a game, and the latter just requires you to work on it starting from Night 2. Refer to Cheap and reliable (30G) for a more detailed guide on how to get that achievement easily too. That should wrap up this completion.

Deathmatch Mode:
There is only one achievement for this mode, and it's for playing a single Deathmatch game. I'm not even sure if a second controller is required, since a match will start immediately when you enter the mode. Simply wait for five minutes to pass (the game gives no indication that this is the match length), and you'll unlock the only deathmatch achievement when the match is over.

Endless Mode:
There are only three achievements in this mode, and they all require you to survive for 5 minutes. This will be the toughest mode because there is no daytime portion to build. It's just nonstop enemies and no barricades or anything else. Solo, this will be a little challenging, and I feel that it mostly comes down to luck with the drops you get. Weapons are one thing, but the powerups are what really makes this mode manageable. Refer to Veteran (50G) for how you need to play this mode. Co-op makes this far easier. More details in the guide, but survive for 5 minutes alone or with others and you'll be done with this mode.

Conclusion:
I found this game to be largely generic and forgettable, but it seems to be pretty polarizing. I was shocked to see online lobbies every time I was playing considering the game came out years ago. Seems like there are people who really enjoy this game for mindless fun and/or leaderboards, and continue to play it. Thankfully it's a pretty simple and quick achievement list, and one that shouldn't have you frustrated or require much skill if you use the strategies I've outlined in the guide. Congrats on the completion.

[XBA would like to thank Necrophage33 for this Roadmap]

Saving up

30
Survive 6 nights without buying anything
As the description says, you need to survive six nights (in a row) without buying anything. To be clear, it must be the first six nights. You can't play a few nights, buy a bunch of stuff, then survive six consecutive nights using the stuff you've already bought.

This achievement isn't too bad. Basically all you have at your disposal is your starting pistol and whatever grenades you collect from crates along the way. I treated these nights like any zombie game: train the zombies behind you and shoot backwards as you run away. Up until Night 4 or Night 5, this shouldn't be an issue. With each upgrade, pick Health Points so you survive longer. Personally, I didn't use anything other than the pistol for the first five nights. You'll want to actually do small, relatively tight circles when kiting enemies, because the pickups they drop are extremely helpful, such as full health or invulnerability. I was able to save up all of my grenades for Night 6, which is the hardest. There are a lot of big enemies, and you'll want to group them up and grenade them to kill them off quickly. Then, make sure to circle back and grab whatever they drop, because the health and/or invulnerability will be essential.

It might take a couple tries, but it's relatively simple to do as long as you make it a point to circle back and grab whatever pickups are dropped.
Combat mastery

30
Survive 10 nights without any barricades, turrets or mines
This achievement is way easier than it sounds. Basically, all you have at your disposal is weapons and grenades. No barricades, no turrets, and make sure you don't even place any mines (since you'll likely acquire some from crates).

The easiest way to do this is with the Chainsaw and Grenades. On the first night, gun down enemies with the pistol like normal. Right after that, buy the Chainsaw. For every single wave, go into a corner (doesn't matter which; I used the bottom right). The reason this works is because while in a corner, only two enemies can hit you at once, significantly reducing how quickly you die. Point the Chainsaw at the approaching enemies and they'll die pretty quickly as they run into it. For bigger enemies (in the Night 8 to Night 10 timeframe), that's when you'll want to start throwing grenades to help with the big hounds and whatnot. Regular zombies go down so fast to the Chainsaw that grenades are a waste on them. Since enemies will be grouped up around you in the corner, all of their drops will be right next to you, making it really easy to grab a full health or invulnerability powerup. As for the upgrades, picking Health Points every time. Spend your money on more grenades (I only used 5-10 per Night in the later nights) and just camp out with the Chainsaw. If you get unlucky with powerup drops, go heavier on the grenade usage to ensure you survive. You'll have more than enough money to buy plenty more.

Finishing the first ten nights with this strategy should be really easy to do. As soon as you kill the last zombie on Night 10, this will unlock.
Untouchable

50
Survive 10 nights without taking any damage
This is probably the most stressful achievement, but it isn't as hard as it sounds. Obviously it's way preferable to do this on the first ten nights of a run, since it only gets harder as you progress. I'll describe how I did it with relative ease.

For the first night, make sure you don't get hit, and take out all enemies with your pistol. Every time you get a upgrade, spend it on Reload Speed. No use spending it on health or regen since you won't be getting hit. Reload Speed makes it easier to take down enemies.

Starting on Day 2, I bought a submachine gun to use as my main weapon, and then I bought enough wooden barricades to protect me from all sides on Night 2 (I bought eight of them and created a 4x4 box with the corners missing like shown in Don't fear the reaper (100G)). This was my setup for Nights 2, 3, and 4, although I used a few grenades on Night 4 to help with the bigger enemies that start spawning.

On Day, I changed up my barricade layout. I picked up the ones left, bought some more, and arranged then in a checkboard pattern like this:

o X o X o X
X o X o X o
o X o X o X
X o X o X o

Xs are wooden barricades and o's are blank spots. I stayed in the relative center. The beauty of this is it forces enemies to weave through to try to get to you, drastically slowing down their advance. It also gives you pretty good freedom of movement. As I earned money I expanded this to add another row on two sides (top and left, for example). I also kept an eye on the Auto Turret. When it went on sale or I had enough money, I bought one. I placed it toward the bottom and mounted a submachine gun on it too. I covered the top half and the turret covered the bottom half. By Night 8 I expanded a little more and added a second submachine gun turret. By Night 10, to be safe and since I had enough money, I put some armored barricades around the turrets. Also by Night 10, I had collected some mines from random enemy drops. I placed those in the o's in the diagram above, so if enemies broke through they'd hit a mine and I'd know to fall back immediately.

It takes a little more strategy than most other achievements, but stay safe inside your base and don't risk venturing outside unless you are 100% sure it's safe. As soon as you kill the last enemy on Night 10 this will unlock.
One shot, many kills

30
Kill 8 zombies with a single sniper rifle bullet in defense mode
Refer to Precise cut (30G) for more information.
Demolition

30
Kill 8 zombies with a single rocket in defense mode
Refer to Precise cut (30G) for more information.
Cheap and reliable

30
Kill 300 zombies with shotgun in a single game in defense mode
For this achievement, you'll want to start it as early as possible (i.e. Night 2) because the shotgun will become pretty useless by Night 10 or so. What's important to note is that you can use turrets to help with this. You need not get all kills yourself with a shotgun. As long as the turret(s) is equipped with a shotgun, it'll count toward this achievement.

As a result, the strategy here is to first complete the first Night like normal with your pistol. On Day 2, buy a shotgun and some ammo. Play through Night 2 with the shotgun and you shouldn't have any problems taking down enemies. On Day 3, buy some wooden barricades to put around you, leaving the corners open for you to get out to get pickups (mainly money). By Night 5, you should be able to afford an Auto Turret (but keep an eye on it in case it goes on sale before that), and mount a shotgun on it. Stay stocked on ammo, and between you and the turret, you should be able to survive to Night 7 with just a simple wooden barricade around you. By Night 7 you should be able to afford a second Auto Turret to again mount with a shotgun. Put them at opposite corners. By the end of Night 7 or Night 8, you'll unlock this achievement (depending on how many grenades you threw to help out).
Efficient usage

30
Use no more than 6 clips during the first night
This is very simple to do and is tough to miss unless you're an absolutely terrible shot. There are only around 10 enemies in the first night, and you need to kill them all without reloading more than six times. You'll typically be able to do this is around three or four reloads without really trying. Worst case, run away from the enemies and let them group up to minimize the chances of missing shots.
Come get some

30
Build and equip four turrets
This achievement requires you to build four separate Auto Turrets (or Advanced ones, if you have enough money) and mount a gun on each one. It'll cost a pretty decent amount of money to do so, but this is the best way to survive to Night 16 to get Don't fear the reaper (100G). Refer to that achievement for more details on a strategy for Night 10 to Night 16.
Private

20
Score 10,000 points in defense mode
Refer to Colonel (100G) for more information.
Corporal

20
Score 30,000 points in defense mode
Refer to Colonel (100G) for more information.
Sergeant

20
Score 80,000 points in defense mode
Refer to Colonel (100G) for more information.
Lieutenant

30
Score 150,000 points in defense mode
Refer to Colonel (100G) for more information.
Captain

30
Score 250,000 points in defense mode
Refer to Colonel (100G) for more information.
Major

50
Score 500,000 points in defense mode
Refer to Colonel (100G) for more information.
Colonel

100
Score 1,000,000 points in defense mode
Points come from killing enemies through this mode. While 1,000,000 points will seem like a lot, it will actually come naturally while going for Don't fear the reaper (100G). Since you have to kill all enemies in every wave, there isn't really a way to vary the amount of points you get. By the time I unlocked Don't fear the reaper (100G), I had just over 1,200,00 points. Refer to that achievement solution for more details on strategy for surviving until Night 16.
Beginner

30
Survive for 2:00 in endless night mode
Refer to Veteran (50G) for more information.
Survivor

50
Survive for 3:30 in endless night mode
Refer to Veteran (50G) for more information.
Veteran

50
Survive for 5:00 in endless night mode
If playing solo, Endless mode is definitely the hardest mode, just because there is no downtime between waves and no building of barricades or turrets to help out, nor buying guns or ammo. It's basically a nonstop flow of enemies, with the only difference being that they drop random weapons for you to help out, in addition to the usual pickups enemies would drop in Defense mode. Since you get no upgrades to Health or whatever like you do in Defense mode, and no way to barricade yourself from enemies, you're entirely reliant on running around like a twin stick shooter. In my experience, literally the only way to survive Endless mode for five minutes is to constantly rely on the pickups that are dropped, otherwise you stand no chance against so many enemies. You'll want to constantly pick up new weapons that are dropped just so you always have ammo, but your entire focus needs to be on looking for powerups that enemies drop, such as Health and Invulnerability. That's the only way to survive. Keep doing tight circles, toss grenades if you get surrounded, and keep picking up whatever you see drop, focusing entirely on that. Shoot nonstop and just beeline to every pickup. Unfortunately, there seems to be a lot of luck involved in doing this solo, because if you get a string of bad pickups, you might be screwed. Expect to take a few tries, but thankfully each attempt is relatively short.

If playing co-op, this is far easier. I played this game and wrote this guide multiple years after the game released, and I still was able to find onling lobbies for Endless mode every time I logged into the game. The main thing with co-op that makes it way easier is that not only are there the exact same amount of zombies but with more people shooting at them, but if you die in co-op, you respawn after a couple seconds without anyone needing to revive you. This makes things so much easier, because as long as everyone isn't all dead at the same time, the game continues. The strategy is still the same: go after pickups nonstop. But, at least if you get back luck with them, as long as someone else is still alive you will respawn and can keep going. My very first time with this game, I joined a lobby and ended up quitting after 10 minutes because we just weren't all dying (there were three of us total). So, I highly recommend just looking at the online lobbies when you play. Even if you don't find one, when you start a run on Endless mode, make it public. There is no downside to some random person joining your game.
Challenger

30
Play through a deathmatch game
As the description says, simply play through a single game of Deathmatch to unlock this. I'm not even sure that a second controller is required, since the game starts as soon as you choose Deathmatch from the main menu. The game gives no indication of match length or requirements, but just be aware that it ends after five minutes. The goal is to kill your human opponents as many times as possible while zombie hordes attack you, but for the purposes of this achievement you just need to finish a match regardless of kills or anything else. Feel free to idle it.
Watch your steps

30
Survive night 9 or higher using mines only
As the description says, you need to survive an entire night from Night 9 or later using only mines. I believe barricades are fine, just no grenades or other weapons.

This one is quite expensive, so you'll need to save up a ton of money. There are a lot of enemies on Night 9 (the earliest you can do this) considering you can unlock Arsonist (30G) for killing 70 enemies in one night, so you'll easily need 70 mines for this achievement. I highly recommend tacking this on after Saving up (30G) as noted in the roadmap (as well as after Grenadier (30G) and Lumberjack (30G)) so that you have a ton of money on Day 9 to spend on mines. I recommend buying a solid 80 mines. Plant them all around the available area in a checkerboard pattern (although I'm not sure that matters a whole lot). Just make sure you cover the map. Start the night and start in the center as enemies all die. Toward the end of the night, you may need to kite a few enemies into remaining mines, but you should have plenty left to do so.
Grenadier

30
Survive night 7 or higher using grenades only
As the description says, you need to survive an entire night from Night 7 or later using only grenades. I believe barricades are fine, just no mines or other weapons.

This is relatively simple to do as long as you build up some money. You'll want a solid 20-30 grenades to be safe, assuming you're doing this on Night 7 or Night 8. Use the strategy in the roadmap, or in Saving up (30G), or in Combat mastery (30G) to get to Night 7 with barely any money spent. Then, load up on grenades. Park yourself in a corner and just spam grenades into the enemies that come. You should have plenty of grenades to take them all out and unlock this achievement.
Lumberjack

30
Survive night 7 or higher using chainsaw only
As the description says, you need to survive an entire night from Night 7 or later using only the Chainsaw. I believe barricades are fine, just no grenades, mines, or other weapons.

This is quite easy to do with the strategy discussed in the roadmap and in Combat mastery (30G). Basically, get a Chainsaw (it's very cheap), and then on Night 7 park yourself in any corner so enemies can only attack from two directions instead of all around you. Aim the Chainsaw out and just go back and forth between the two enemies. You should have no problems surviving even without good powerups, but if you get health or invincibility, all the better. Invest your skill points in Health Points to make this very simple to do.
Arsonist

30
Kill 70 enemies with flamethrower in one night in defense mode
As the description says, you need to kill 70 enemies with the flamethrower in a single night, not cumulatively. I believe this isn't possible until Night 9, as there just won't be enough enemies in a single night before that.

As was the case with Cheap and reliable (30G), you CAN use turret(s) to help with this, mounting a flamethrower on them. I found that to be largely required here, as the flamethrower just seemed absolutely terrible in taking down enemies. Personally, I did this right after Combat mastery (30G) since that achievement got me to Night 10 with barely any money spent, meaning a ton was saved up. I then built two Auto Turrets, mounted a flamethrower on each, bought a flamethrower for myself, and surround the three of us with Armored Barricades. Spend the rest of your money on ammo, and you plus two turrets with flamethrowers will have no problems surviving the night and killing all enemies.
Not so fast

30
Have 25 enemies frozen at the same time in defense mode
Refer to Precise cut (30G) for more information.
Precise cut

30
Kill 15 enemies with a single laser beam
For all of these achievements that require you to get kills with weapons, I found a very reliable way to do them all using the exact same strategy, and you can actually do them all together, essentially.

Start up Defense mode, and you're going to want to get to at least Night 7 or 8 so there are enough enemies. Night 9 might be a safer bet. For the first Night, just use your pistol. On Day 2, buy the Chainsaw. For all upgrades, spend them on Health Points. For every Night up until at least Night 7, you're going to use the exact same strategy as Combat mastery (30G): camp in the corner with the Chainsaw out, throwing grenades here and there as needed, and you should have no problem surviving the first six or seven nights like that. You'll amass a ton of money and it only takes like five minutes to get through those nights.

Once you have enough for the Freeze Ray, buy it and at least 10-15 ammo (that's all you really need). Then, whether it takes another Night or so (continue using the same Chainsaw strategy to survive), buy whichever weapon you want to try for kills with (Laser, Sniper, Rocket Launcher). Buy it and a few ammo (10 is plenty, but 20 is good). Head to the same corner you've been camping in and start the next night. Immediately switch to your Freeze Gun and just fan it in front of you to cover the area of enemies. Do this over and over while enemies pile up in front of you. This both works on Not so fast (30G), which will unlock in the process, but it keeps enemies next to you frozen so that you don't take any damage at all. Once you've gotten a large amount of enemies frozen on screen (pretty much the entire screen should be filled, to be safe), switch to your weapon of choice (Sniper, Laser, or Rocket Launcher) and use it accordingly. For the Sniper and Rocket Launcher, just fire into as many enemies as you can, and aim for the small regular zombies since they'll die faster. Minimize the bigger enemies because they likely won't die with the rest and won't contribute to the achievement. For the Lazer, you'll want to sweep it over the enemies back and forth a few times so that many die at once.

In the link below, I took a clip showing this method in action. Apologies for the darkness, but apparently it's really dark when you're in the corner of the map. I had no problem seeing on my TV but it's nearly impossible to see me in the clip. However, you can still see that I'm in the bottom right corner, and you can see how I fan out the Freeze Gun shots to keep building up frozen enemies in front of me. I unlock Not so fast (30G) while doing this. Then, I switched to the Laser and swept it across the enemies a few times and unlocked this achievement there as well. Like I said, as for the Sniper, fire into a long line of regular zombies to increase your chances.

Don't fear the reaper

100
Kill a reaper
Reapers start spawning on Night 16, so this achievement requires you to get that far, which is the farthest you need to go in Defense mode. Getting that far will require a decent strategy, because many guns stop being effective after Night 10, and even grenades take a few to take out bigger enemies.

For the first 10 nights, you'll want to be judicious with your money. I recommend the Chainsaw since it's the only thing that doesn't require you to buy ammo, and it's incredibly cheap to buy. Using the strategy in Combat mastery (30G), you don't even really need barricades or anything other than a few grenades for the first ten nights, and you'll amass a ton of money. Along the way, keep an eye on Electric Barricades, because if they go on sale during a random day, start buying them up. Start with 8, but eventually go up to 16. Do the same thing with Auto Turrets - look for a sale and start picking them up. Ideally, get four of them. By Day 10, if you mainly just used the Chainsaw, you should easily be able to afford 8 Electric Barricades and at least two Auto Turrets. As for which weapons you mount on the turrets, it's not critical. I got to Night 16 with four shotgun turrets, but you could also use submachinegun ones. Sniper ones are definitely the best, but that's incredibly expensive, and you definitely won't be able to afford four turrets AND four sniper rifles, so stick with the cheaper guns - use either shotgun or submachinegun (or a mix of the two). For you personally, get a sniper for yourself.

As for the Electric Barricades you buy, arrange them like this:

o X X o
X o o X
X o o X
o X X o

The Xs are the Electric Barricades and the o's are blank spots. It's important to leave the corner open because enemies can't fit through but you can. If you close them up, you're unable to leave to pick up enemy drops. The middle four o's are where you'll place turrets. Once you can afford another eight Electrice Barricades, place them around the above setup as such:

o X o o X o
X o X X o X
o X o o X o
o X o o X o
X o X X o X
o X o o X o

This still gives you lanes on the diagonals to move in and out of your structure, and then extra pieces on the corners makes it even longer for enemies to get in. Your turrets will do a lot of damage. Build them up until you have all four with mounted guns and you'll unlock Come get some (30G). Get yourself a Sniper when you can afford it and it'll do serious damage. By the time you reach Night 12 or 13, you should be able to afford a bit more. I started putting Propane Barricades around the structure above just to help cut down on enemy numbers. Keep yourself stocked on ammo first and foremost, as well as grenades, and keep your barricades replaced as needed. You don't need to refill ammo for turrets. Play it safe and don't venture outside unless there are no enemies on your corner and you're going for pickups. When you get to Night 16, take out a reaper and you'll unlock this achievement. They go down in a few sniper shots.
Abandon all hope

30
Abandon all hope ye who enter here
(1)
This achievement requires you to die on the first Night of the game. Start up a new Defense run and just stand there, letting enemies kill you. This will unlock after you die.