Survive the Eye Poke Machine

Kill 4 enemies with the same Ripper blade

Kill a Necromorph with every Weapon in the game (single player only).

Purchase the Advanced Suit

Sever all three tentacles of a Lurker with one Line Gun Primary Fire shot (single player only)

Kill a Stalker with the Seeker Rifle while in Zoom Mode

Collect 10 Schematics

Defeat the AI

Impale an enemy and make him fly through the air for 17 meters - it must stick to the surface

Kill the Tormenter

TK Impale a live Slasher to a surface using a Slasher's arm - it must stick to the surface

Survive the Train Sequence