Cappella Magna Achievement in Vampire Survivors

Each normal stage in the game is unlocked by reaching a new level milestone on the previous stage. So, Stage 1 you need to reach level 2, Stage 2 you need to reach level 40, Stage 3 level 60, and so on.

You'll likely find that, when you start the game, you don't struggle much to get up to level 20 and then level 40. Getting to level 60 will likely take a few more upgrades between runs. Getting to level 80 will be the hardest, as it'll require you surviving until close to the 30 minute mark, and Gallo Tower is pretty challenging early on, especially its boss at 25 minutes. To get that far, this is the build I recommend (same as the build you'll see in other achievement solutions):
 

• Evolved Santa Water (Santa Water + Attractorb)
• Evolved Axes (Axes + Candelabrador)
• Evolved King Bible (King Bible + Spellbinder)
• Evolved Lightning Ring (Lightning Ring + Duplicator)
• Evolved Runetracer (Runetracer + Armor)
• Song of Mana, or starting weapon (not evolved)
• Spinach

This is a reliable build for pretty much every stage, especially close quarters ones like Inlaid Library, Gallo Tower, and Capella Magna.