Very good for your first jam! Character movement itself felt really good. However at some parts the jump&run elements were kinda too hard IMO (like at the ending). Not that it was unbeatable, but you had to jump pretty frame perfect I think. Give us just a couple more frames room to land the jump and I'm good :D
Some visual effects when an enemy is hit would also be pretty cool. Oh and also you can stand on the turtle-kinda enemy. I was chilling on one, it dashed down into the sludge and I kept respawning in the sludge until I died and had to start over. Oh and also would be pretty cool to not start in the tutorial level again.
Overall a pretty good experience, congrats on completing your first jam! :)