Hi everyone!
If you need help in making time manipulation mechanics, I wrote a tutorial for rewinding time. I used this technique in my submission for last week's TriJam #125, and after that I noticed this lovely jam which my game would've been a good fit. I'm not yet sure if I'm gonna come up with something for this jam, but I decided to help fellow programmers to get started with time manipulation. Don't worry, it's not anything difficult, the tutorial's minimal working example has just about 60 lines of code.
Tutorial uses Godot, but there are some notes how some concepts convert into Unity/C# and the example code is very clear even without prior knowledge of Gdscript.
I hope this will be of assistance: https://axu-ap.itch.io/rewound/devlog/267320/time-rewinding-mechanic-tutorial