I legitimately loved this game! The idea, execution, and aesthetic is so rad and I would love to play a much longer version of it! I do have some feedback if you would have it:
Feedback 1: When the player is near the edge of the screen it becomes hard to get a good jump because the cursor hits the edge of the screen.
Feedback 2: Killing the enemy seems to have no bearing on level progression. It would be so cool to see a "pacifist" and "genocide" type thing to make them more important.
Feedback 3: When in the air and trying to do another jump it is very difficult and finicky. It would feel super neat to have some kind of limited slow-mo when trying to do a double jump.
Other than that I think the game is already super fun and with a bit more works could be a killer!