Crazy addicting. Once you understand how the game works, it gets REALLY fun! There's something very cathartic about getting a big strong boost. Outside of some of the things mentioned by the others, I'd also like to suggest allowing the player to retry using the keyboard, since having the hands on both SHIFT keys and Space to them go to the mouse for restarting didn't feel as intuitive!
The art is very stylistic and reminds me a lot of your game from last jam, and that's not the only similarity I got! This game also feels similarly relaxing, even if you have three speed demons flying after you. I also love how both our dragon and the evil dragons look. The game absolutely exudes a magical energy from it.
The gameplay itself also ends up feeling relaxing because of the way you're supposed to move. Doing those waveform movements makes the gameplay itself feel quite beautiful in a way. The music choices also play a big part in how good the game feels in terms of atmosphere.
I enjoyed this a lot. It's fun!