I love the idea behind this game, it really feels so different from any other rhythm game that I've seen or played (as someone else said, very barely resembling stepmania or rhythm doctor). It would work better with the dice progressing when you move to the 6-face and having a hit window, with some sort of indicator - metronome, approach circle, pointer, etc. - to make you know when to hit. This would feel better in gameplay than having it progress on the beat, as high/random input latency from the browser feels pretty killer.
But, within the scope of GameJam, this is brilliantly made, I'm just another picky rhythm game player. I'm excited to see how this game progresses, if you continue to work on the game! I would love to eventually see this having an in-game editor so that users can make their own maps, too!

