Collect 100 logs

Kill a Stalker with the Seeker Rifle while in Zoom Mode

Kill a Brute without taking damage

Destroy the Tripod Nest

Kill 50 Necromorphs while they are in Stasis (single player only)

Kill 4 enemies with the same Ripper blade

Defeat the AI

Collect 10 Schematics

Keep any vehicle at 30mph or over for 5 or more minutes.

Finish the story on Medium difficulty level or higher.

Sell 5 vehicles to Mike Bruski at the scrapyard.

Pay a visit to an old friend.

Complete Chapter 12.