What a lovely game. The mechanics are simple, but the fact that jumping increases your speed indefinitely (or at least I didn't reach a limit) adds a very interesting layer of difficulty.
I had a few minor issues, like the character not reappearing on the other side when leaving the screen. I don't know if it had to do with my screen aspect ratio (21:9), but it didn't affect the gameplay much; I just had to reset the level.
The way the camera shakes when the player is going too fast works really well!