Liked the combat system. I think rewind mechanic can be well implemented in turn-based combat (like jRPG's or roguelikes). Control seemed weird at first (like F as an attack button, that's pretty unusual), but you can get used to it. Also, I think I found a bug - when you start the fight and press the Rewind button, then enemy's health reduces to oneshot amounts, so it is easy to defeat them)
Another thing I wanted to suggest, if you don't mind: try not to scale or stretch pixel art - It makes pixels look weird. I am not a great artist myself, so that's just an advice from your fellow game dev for the future.
Anyway, I liked you game, congrats on the jam!