Very interesting. Agreed it's short, and I was a bit unsure of why other hallways existed when there's nothing in them. Overall though, I really enjoyed the visual appeal. I think the movement works quite well for horror, as it really feels sluggish and distorted, plus the CRT effect just adds to that analog horror vibe.
I'm curious to see how this would be expanded, since the movement and visuals seem pretty polished considering they don't really contribute to the riddle mechanic.
I'd also be really interested in seeing how scary a game could be just off the riddles it gives you. I for one am not a huge fan of the 'run from scary monster' type of horror game, and riddles/logic puzzles actually seem like they could make a unique gameplay style, since we don't really see it often.
Hope this helps!
-Zach