Last night, my review briefly touched on the disappointing enemy AI in Aliens: Colonial Marines — often, Xenos would run straight at you. According to this video by PCGamesN, it gets worse.
You can straight up run through the aliens, who forget about you once you're far enough (and by "far enough" I mean "once you're behind them.") Mind: this video is the game on a higher difficulty — 'Hardened'.
I suppose the bright side to this is, if the awful shooting sound effects are driving you up the wall, welp. Maybe you don't have to shoot at all.
Aliens: Colonial Marines - Pacifist Mode [PCGamesN]