Obtain all keys and use them all.

Shoot down a Hunter or an Eliminator while they are jump attacking in the air.

Fight off the Proto Tyrant.

Defeat a zombie by stomping on them.

Get picked up by the Infected Bat.

Play the piano using Rebecca.

Defeat an enemy by burning them.

Use a Green Chemical.

Defeat Centurion.

Create every type of item available in the Crafting menu.

Push away an enemy after guarding in the story.

Defeat Osmund Saddler in Separate Ways.