Purchase an upgrade.

Cleanse the ring of stones.

Collect a bow.

Mickey revived Oswald while playing co-op

Acquired a Collectible Pin for the first time

Find 25% of all documents.

Defeat the infected Hand of Aegaeon

Clear the "Ground Zeroes" mission

Complete SUBWAY level.

Perform 50 headshot kills in the single player campaign.

Force an enemy to drop dynamite that kills two people when exploding.

Complete one optional tomb.

Collect 99 coins