Chapters 5 and 10 were the scariest for me. The invulnerable ubermorph just makes me crap myself. It's perfectly alright jumping and being able to kill the necromorphs, but when it doesn't die that's the scary factor for me.
Deus Ex Achievement Guide | xbox.com
Retail Completions: 38 | Arcade Completions: 15
Seriously 3.0: Total Onyx Medals - 24/65 | Level 86
Currently Playing: Assassin's Creed III, Borderlands 2