I really dig the artstyle - it's cute, charming and easy to read. The music is A+, relaxing, interesting enough to grab my attention, yet not distracting despite that. Took me a few seconds to realize you could hold down the WASD keys to control your movement direction as opposed to tapping them, but from there it was smooth sailing (pun intended.) The visual distinction between the speed powerups/powerdowns is great and made it immediately clear to me that one of them should be avoided, although I walked into one of the powerdowns anyway to see what would happen.
The only real critical feedback I can give is that it took me a little bit to figure out how to start the game from the initial high score screen.