That was fun! I really liked the graphics, and the gameplay started off easy but got progressively more challenging. It definitely could have used some sound effects or background music at least. It also could have used some collectibles to entice the player to take more risks on challenging platforms.
There’s a lot you could add to make the game more challenging and engaging. You could add some sort of tightrope or just a thin platform that the player has to navigate while enemies shoot projectiles at you. You could add items like speed boosts, an extra jump, or a glider. You can make levels that are more vertical and require you to fall down avoiding obstacles, or go down some kind of slide.
Start experimenting with different mechanics and I think you could turn this into a fun platformer, or maybe even a multiplayer game