Small details they may be, but when they're details on Gearbox's upcoming Aliens squad-shooter, you'd damn well better lap them up. First up, the game won't be restricted to claustrophobic indoor environments. While they'll obviously play a big part, there'll also be outdoor sections as well, giving you a breather from the RELENTLESSLY OPPRESSIVE DARKNESS. It also won't feature your traditional progression through levels, either. Rather than simply advance from beginning to end, some levels will require you to "make a stand", asking you to set up turrets and barricade doors in an effort to hold an area from a swarm of incoming bugs.

Two more: first is that the game will feature proper acid blood, which won't just injure you if you get too close, but will also have minor effects on the level's environments. Second is that the game will feature quick-time events. Sorry to save the bad news for last, but hey, you had to hear it some time.
Aliens: Colonial Marines gameplay info [GamesRadar]