Defeat 50 enemies with stealth attacks

Defeat 20 enemies with the Pistole

Defeat 20 enemies with a single punch, after softening them up with gunfire

Find ten treasures

Defeat three enemies with one explosion

Find the Strange Relic

Defeat 20 enemies with hand-to-hand combat

Kill 3 Helghast using an M82 or StA52 assault rifle without releasing the trigger

Double Teamed with every Drowning Doom unit

Acquired 3,000 Fire Tributes

Visit the Insomniac Museum.

Complete a Challenge Mode playthrough.

Rescue all Zoni.