My reflex answer was, yes, obviously.
But thinking about it, probably not, a lot of the most famous horror films aren't at all scary. No-ones scared of Friday the Thirteenth, Jason is a punchline. The whole slasher genre is now pretty much a funny game you play with friends taking bets on who gets knocked off and how. Even the Evil Dead films, were they really scary? But they were entertaining as
So it's twisting the definition a bit, but if we say something is horror if it has elements that are used in scary films and based around some weird monster, with a threat of death, then yeah I don't see why we have to pin it in one emotional box if it fits others. There's got to be something about it, it has to contain elements that we would have at one point considered scary, and to be honest there should at least be a jump scare or something, but nowadays a lot of the draw of horror is a kind of indulgent man-hunt thing and Dead Space has an opportunity to be in on that market