Amazing project, well done!
Mechanics are solid and mesh well together (There might be a bit too many that you learn in one go, but GameJam so that’s fine). I felt a bit of “looseness” when doing certain jumps, but that’s probably the physics engine faffing about.
A couple of things for usability. A shadow under the player model would be great because it helps gauge jumps better. A bigger reminder that you’ve used your mid-air shift already would be useful for the longer jumps. I’d also move the dead zone that restarts the player a bit more up, the game has a really nice rhythm and after failing a jump you don’t want to wait too long before trying again.
All in all, great project! Definitely portfolio worthy if you’d like to use it for that.