First, the music is way too much of a clichè feel-good music. Combine that with a platformer, which can be frustrating at times, and you are angry and then there is this passive-aggressive music telling you to be happy, but you aren't, but you want to be happy, which makes you less happy... and it goes on and on.
Also, the animations of the main character aren't smooth. Maybe you use an incorrect canvas size for the sprite sheet?
The movement is also not that great. It's okay, and from a programmer standpoint fine. But if you look at platformer design there's a lot that you can do just with the movement. I recommend watching this excellent video from Game Maker's Toolkit. It helped me a lot to get the movement right for our game.
And the level design itself lacks focus. There is no clear pattern for how the levels are laid out. You had some cool ideas with the rewind mechanic, but you can explore them in a much more focused way, which makes for smoother playing experience.
The HUD for the time that you have during the 'run it back' mechanic is also way too small. Maybe it didn't scale on my UHD monitor, though.
The game is also really short.
I hope my feedback isn't too harsh. I always look at games from an objective design standpoint. I assume it was more of a programming challenge for you. Well, and for your first jam game, it's alright. But there's much more to learn. Keep at it, and one day you might get somewhere!