Hey, I really love a lot of things done on this game. Here to share my thoughts on it :
1) The rewind mechanic, while simple in nature - I think it blends well with the game feel. The rewind dimension reveals puzzle solutions, and at one time - a very scary world. And as a result, the normal world feels more 'safer'. Given enough time, you should explore this design philosophy to create some interesting pacing in horror games - where you alternate between a safe world, and a dangerous world - and you could juxtapose that somewhere in the game. Love it!
2) The music and atmosphere. I am seriously bad at jump scares so thank god this is not a jump scare game. The oldies radio in the first room helped me settle in a bit, while all the gruesome detail around contrasts that well. I think you missed the opportunity of playing the music in reverse when you're in the rewind world (or maybe you did and I missed it - thinking it was normal..). Despite its simple graphics, I think you did well on setting the mood with the limited FOV, slow movement and gradual reveal of plot details.
I have a few thoughts on other things you can keep in mind, some of these are subjective:
1) Mouse sensitivity, understandably there are limited time to implement an options menu - I don't have one myself in my game. But the problems become glaringly obvious when playing a first-person game like this as small movements cause huge sweeping motions. Consider an in-game mouse sensitivity option - maybe.
2) There was one time when the game froze shortly after starting the game. No big deal - just restarted the game. I almost thought it was intentional design (you know, going with the game title of it might just be in my mind.. idk). Haha - considering exploring that.
3) Small polish details such as making the artwork upside down in the rewind dimension - I think it's such a small detail, but can add a lot to the atmosphere from an artistic perspective. And also, do you know that we can't actually properly read words or read the time when we're dreaming - you could draw that parallel to when you're in the mind (in the rewind dimension?) to how to decorate the rewind dimension.
I probably messed up a lot of the supposed story didnt I.
4) The last room needs more guidance - I typically search from left to right, so when I was hugging the wall on left side, I saw the 'couch' from behind and activated it without realising what it did. I think for such a crucial scene, maybe just a bit of light - to show 'couch' at least? Consider that.
5) The line of sight (or circle.. thing) might be too small - it becomes almost difficult to try to navigate through places. This comes from an absolute horror rookie though. I think if you want to keep the typical low line of sight - maybe you can add on top a flashlight with limited batteries so it still forces players under the low LOS to conserve batteries - and always keeps them tense.
I know it looks like theres more cons than pros but you know how human psychology goes - we remember the bad things more than the good things. With that said, I thoroughly enjoyed your game and you can take my word for that. It's such an enjoyable short experience and I had to take one for the team and play a horror game for once. You've checked some boxes of a good horror element so keep it up!
Loving it - hope to see more from you!