Defeat the Energy Leech

Defeat the Octaking

Defeat the Battlelord on the Hoover Dam

Defeat the Alien Queen

Defeat the Battlelord in Las Vegas

Defeat the Cycloid

Unlock the secret closet at the end of the Forkstop

Win a game of Alien Abortion in the strip club

Knock out the talent at the talk show

Shoot down the blimp above the stadium

Kill all the catfish in the underwater level

(1) 

Drink all of the beers in the strip club

(2) 

Listen to all phone messages

(1) 

Find all 3 helmets in the SP campaign

(1) 

Watch the credits all the way through

Complete the SP campaign on Insane Difficulty

Complete the SP campaign on Hard Difficulty

 

Complete the SP campaign on Normal Difficulty

 

Complete the SP campaign on Easy Difficulty

 

Carry the gold pistol through the whole SP campaign

Discover all Ego cap awards

 

Drink beer while on steroids or vice versa in SP

Doodle something on the whiteboard in SP

Use a Holoduke in SP

Take steroids in SP

Drink a beer in SP

Earn a 1,000,000 pinball score in SP

Win air hockey with a score of 7-0 in the strip club

Blow up 5 enemy gunships or dropships

Put a Trip Mine on a live alien

Look at every page of a calendar

Shoot down 20 alien fighters

Get hit by 10 Pregnator bombs

Find and steal a piece of poo

Get knocked down 10 times

Kill 3 aliens at once

Kill 30 aliens with headshots

Eat 10 pieces of food during the SP campaign

Kill 15 aliens with melee attacks while on steroids

Kill 10 aliens with tossed objects

Kill 10 aliens with environmental explosives

Kill 6 aliens with the forklift

Kill 15 aliens with the monster truck

Kill 15 frozen aliens

Kill 10 aliens with Trip Mines

Execute 20 aliens

Foot stomp 12 aliens

Kill 250 aliens

Kill 100 aliens

Kill 50 aliens