Defeat Nemesis on the rooftop.

Defeat two enemies with a single shot.

Withstand the zombie siege.

Escape from uptown Raccoon City.

Improve a weapon.

Defeat Stage 2 Nemesis.

Escape from Jill's apartment building.

Pass through portal on the snowy mountain peak.

Unlock the 2nd act.

Clear any level with disappearing arrows modifier.

Clear any level on normal difficulty and get at least 50 combo without any modifiers.

Finish the tutorial.