Cute game, the simplistic art style and animations with the particles work really well given the time constraints.
I think the spikes hitbox needs to shrink a little so you can get closer to the spikes without dying. There were a lot of moments where I felt like I didn't touch the spike (obviously did), making the hitbox a little smaller will help a lot with game feel.
I didn't like how as soon as you let go of a directional key in the air the character just stops. It feels really rigid, and forces you to hold the directional key and have to try and let go in the last seconds so that you don't move while on the ground.
Maybe you could show the entire level at the start, or have a button to toggle full map view. Because some of the levels are almost impossible to beat first try because you kind of need to explore first.
Well done, you did a really good job!