Really cool game overall, I especially like that you build your own level. The visuals and the sound also tie together nicely and the game loop works well as a whole.
My only complaint is that the movement feels a bit too rapid/jaggy in my opinion, as you go from standing still to full speed immediately - maybe having a bit of acceleration before reaching your max speed would have helped with that but that is honestly personal preference.
All in all it is a great game though, well done! :)