Fifteen Minutes

Excellent game! As others have said, it's well worth challenging yourself to complete it without the walkthrough. Word of advice, though - do NOT save after answering any questions UNTIL you've been given the okay by the principal!! Needless repetitive hell when you realize you've messed that up. (Otherwise, proud to say I finished in a matter of hours, though I did have to check the walkthrough after somehow failing to examine the rope :P)

As someone else said, the clock tick is really inconsistent, so undo is your best friend here. Above all, it's not as hard as it seems, so long as you keep notes on the offset from current time for each version of yourself.

This is a nice, humorous puzzle game involve time travel and paradox management. You must take copious notes in order to arrive at the solution. The timing in the game feels somewhat fiddly -- things occur at certain times and you must know to the minute when they do, but it's hard to tell if they happen before or after the clock tick. And I'm pretty sure the time travel mechanic is handled inconsistently -- sometimes I'd arrive before a clock tick and sometimes after. This meant that I had to experiment to find the correct timing. I suppose it's possible to beat this game on your first playthrough, but extremely unlikely. However, once you've figured out how to proceed through the game, subsequent playthroughs can be tedious, particularly since the machine is tedious to operate after the 20th time or so. And it's entirely possible to miss a crucial action near the beginning and have to restart.

I really liked the premise of the game, and it's reasonably solid in execution. With a little polish, it could go next to Suveh Nux on my shelf of favorite one-room puzzlers.

Absolutely requires taking notes during the first playthroughs, no superficial elements here, everything's important.
Walkthrough required for normal human beings without OCD or special IF-game skills.

I loved the minimalistic and detailed approach, and how most elements referred to each other in a circular fashion, so that instead of exploring new rooms with new objects, the exploration happens through moving through time and re-living the same instant in the same room. Reminded me of one of the fantastic Ben Jordan games (go check if you haven't) where the hero remains in the same room, but slight and scary changes happen to the room.

Unlike other commentaries, I didn't experience any randomness in my playthrough (THANK GOD!!), but one could easily imagine how this game could become Hell if it ever got expanded with additional layers, randomness, objects, characters..etc.