There's a thread over at Story Games about using Dead of Night for a Space Hulk/Alien/X-Com style game. I've chimed in with my thoughts, but will repeat them here like the verbose man I am.

Dead of Night would work quite nicely for an Alien/Space Hulk style affair, although I wonder whether Terminators might be a bit too hard to fulfill the role of victims. Colonial marines on the other hand - they have cannon-fodder written all over them.

Tweak survival points slightly so they represent things like running out of ammo, the motion detector going bonkers and your npc teammates getting dragged off into the air ducts.

Tension needs to start low but spike suddenly, before dropping again. So maybe insist the GM spends at least 2 or 3 at a time to rapidly drop the tension after an encounter. I guess you're looking to encourage aliens that keep coming back for more, so maybe use tension for protect and assault checks. You're also looking to keep people on the run throughout the ship, so maybe use it for escape checks too? Or you could use it for identify checks so the marines know something's coming ... just not what.