Very good for a first game! But since you use pixel art, you really should set Project -> Project Settings -> Rendering -> Textures -> Default Texture Filter to Nearest, that will get rid of the blur and make the graphics nice and crisp.
I liked the powerup-based surreall exploration, and if you want to improve your platformer development skills, I recommend you next look into coyote time, jumb buffering and things like that, here's a good starting point: a video by Jonas Tyroller