Great presentation! This game has such a cool vibe, time trial and racing were my favorite modes. Great art, music, sound, and UI. The transitions were extra slick!
I lost fairly quickly in the knockout and battle modes, I wish there was a way to do a practice run or a tutorial the first time through on a new mode. My only other comment is I wish you didn't have to click so much after depositing the quarters, but that's just a personal preference and didn't diminish the actual gameplay. Well done!