Take Knifey's advice and stab Gene in the gut.

Juggle an enemy in the air with at least 5 shots.

Kill Slumsley.

Isn't it pretty? That's going on the fridge.

Now look who's extinct!

Destroy a Charlie Doll.

Defeat zombie Brad.

Defeat Nemesis on the rooftop.

Improve a weapon.

Craft an item.

Escape from Jill's apartment building.

Complete mission "Children of the Vault".

Complete Leon's story.