The game is pure monster movie horror flick. The necromorphs are really quite awful looking, sounding and acting. There are a couple of monsters I wanted to dispatch ASAP just to stop the horrible sounds they were making. Ramping up the "ick factor" is the fact that the monsters are most quickly dispatched by dismembering them. That's right, there's no quick shotgun blast to the brain-pan for these monsters. You literally have to rend them limb from limb to get rid of them. Yes, it's as gross as it seems.
Adding to the horror aspect is the overarching theme of madness. The plot tries to keep the player guessing as to who is sane. It's ambiguous to the very end, and adds quite a bit to the unsettling ambiance of the game.
Another interesting aspect is the zero-g gameplay that occurs periodically. During these times you're able to run and jump from place to place, dancing on the ceiling like an interstellar Lionel Richie.
There are some problems with the game. The Ishimura is evidently constructed of crepe paper and you have to repair nearly every system onboard in order to complete the game. By the end you really begin to wonder if you'll need to fix the slurpie dispenser in order to get the hell out of dodge. Another is the unrelenting ickiness of everything. It becomes depressing over time, so much so that I didn't want to play through it a second time. The game could have used one or two lighter moments to fix the pacing of things.
As a fan of games where you send zombies and their ilk back to their graves, I thought this was well worth playing. It takes a fair amount of time to finish, but since I really don't want to play this ever again I'm torn between saying to buy or rent this game. Since I'm cheap, I say rent it. You'll probably have to renew it to finish the whole thing, but it's still cheaper than purchasing it.