Some more rewarding feedback for successful actions would be cool
Eg. VFX / sound when I bounce
Some visual reward for gaining momentum e.g. wind, sparkles, whatever in the background or being emitted from the player. Getting a lot of forward speed is the most rewarding thing in the game, so it would be good if the game could emphasize that feeling of accomplishment.
Just think about what actions you want to reward in the game, and then make that feel rewarding!
Simple mechanic but with an interesting skill ceiling.