I enjoyed this game very much. I played it on stream.
In addition to the time mechanics advertised on the box, I can also rewind time to any checkpoint I save at, which means I can go back to any of them and do something different than I did last time, and this creates a forking-pathed list of alt timelines that I can go back to at will. "oh in this timeline i got the heart, but i didn't turn on the machine..." etc.
When I rewind, I lose physical upgrades (HP, energy, buttons pressed), but keep information (passwords, new moves, better guns). Midway in the game, I was making routes that started me at the beginning of the timeline and used all the moves/guns I had so far to collect all the HP/energy upgrades I knew about so far, all in as little time as possible so I could use the rest of this timeline exploring and progressing.
I have one criticism: the puzzles with red doors shutting behind you are VERY unclear in what their win condition and mechanics are. That puzzle needs to be made WAY more clear.
1. I didn't realize until after banging my head against a puzzle for a long time that I can charge-shot any door and reset the puzzle.
2. I didn't realize until after banging my head against a puzzle for an even longer time that it is not necessary to end the puzzle *at the exit door.* That is incredibly unintuitive. I kept trying out routes that would have gotten me trapped after all the doors were shut, and I thought intuitively that was a wrong answer. But no apparently that's... the correct answer? That made no sense.