Your game is rad and you should feel rad. Great concept and execution. Everything feels like it belongs together, from the art to the music to the gameplay.
I would say that if this is something you want to pursue further, there are some small quality of life things that could be improved on. A sense of direction for the player would be really nice. Maybe a sound when you get close to a collectible or a glow where they would be if they were in plane?
Second, the checkpoint system is a little too forgiving. I fell off twice, and each time it put me in front of collectibles that I don't think I was anywhere near before and even had the plane lined up so that I could see them. I think it might be better if it just remembered the platform you were on last and put you back there.
Either way, excellent game and one of the best in the jam that I've played.