Nice. The art , level design and music all work well together. I also submitted my first ever game to this jam, so really great to see someone else in the same boat.
Some little nitpicks:
- I think there's some kind of purple box around the character. I think it would look a little better for it to be transparent. Either that or the background is playing tricks on my eyes.
- You probably could hide the mouse in game so it's not on the screen when not being used.
- I'm sure you know what you want to add, but enemies and obstacles could make it more engaging.
Good job!