It has always been an atmospheric monster-closet style horror, with very very light survival elements. Limited ammo/health definitely helps with the tension, but usually the game is easy enough that these never become an issue like in actual survival horror games. It's definitely a lot of fun, and the "puzzle" style combat definitely keeps the game interesting instead of just being point and shoot.
Co-op has a lot of potential, since it will allow for weapon combos, and maybe will be able to increase tension with L4D style enemies that incapacitate one character, forcing the other to come save him.
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_foolmo_
'he says listen to my story this maybe are last chance' - ertyu quoting Tidus