Hmm, this is a decent little arcade game you got here! The whole aspect of being stuck to a track and only being able to slow down or speed up makes dodging a rather novel experience, and the enemy design, such as the muncher that is always chasing you, adds a nice element of push-and-pull that forces you to speed up away from slow, boring, cautious play. It's a nice, simple game and I had a few times where I got into a really addicted trance state, so well done.
If I did have a few points for feedback they'd be:
I was a bit disappointed that the game didn't evolve past its initial setup: would've loved if, as you reach certain thresholds, the game starts introducing new enemy types, obstacles, and so on. With only a incremental speed upgrade, the game starts to get quite dull, and the unlocking of flavors isn't that exciting.
Speaking about flavors, I was confused on what the point of the flavors were at first. Call me an idiot, but I kept selecting new ones, starting a game, and being confused as to why nothing was different, only to realize later on that you need to press a button to activate them: feels like an unnecessary step as you'd think selecting them would just immediately change it.
Was a bit disappointed that the game doesn't save your previous top score and flavor unlocks on a revisit.
Also, it's a minor wish, but I wish that the character itself would change to reflect its life, instead of the life counter being tucked away in the corner where it is difficult to see in the action. In a manner similar to Balloon Fight, you could've made the character lose a ball for every point of damage they take.