The art is very cute and the lighting effects are nice :o! I wish there was more I could play with because I really like the idea (I couldn't get past the vertical tunnel because the magnets weren't working after the first two sets).
Something I think might help improve the game is to add checkpoints. I found myself dying a lot at the tunnel and restarting from the beginning each time would get frustrating.
Second is the jump seems to have a really significant input leeway, where I'd let go of the button long before landing but would jump once more.
And lastly it seemed like the collision with the corners of pits wasn't a corner but a slope? I often would fall into the pit from being what looked like far enough from the edge to be safe (also meant running jumps were met with death often as well... :( ).
Congrats on your first game!