Clock Tower. Can a 2D side-scrolling be scary ? It sure can. Maybe it's not so scary, as it is tense. The atmosphere is fantastic and crates perfectly the feeling of the helpless protagonist trying to escape the seemingly supernatural serial killer inside a huge, sinister mansion.
Good sir, can you be more specific on which Clock Tower do you speak of exactly?
- Clock Tower on SNES, which I never played, but people describe it as a unique game for SNES. It's about the only slow-paced game on the entire console. Maybe too slow to be scary and tense, actually.
- Clock Tower on ps1, which I personally consider one of the most tense and shitbrickin' games in the genre.
- Clock Tower 2 on ps1, which is overall a good sequel, but it's basically an add-on, with not a single new idea, but rather prolonged experience.
- Clock Tower 3 on ps2, which I missed and eager to know more about.
Edit: Nevermind, just noticed "2D" in your description. I figure it's SNES then. Seems like I fuck my eye, sorry.