Omg, wildly creative mechanics. Honestly one of the best entries I've played so far. I love me some Crypt of the Necrodancer, so naturally this game appeals to me right off the bat haha.
First off the instructions were a lil too overwhelming hahah. Some pacing there would be great - breaking them down into separate parts or slides would've helped a lot!
Gameplay wise, I would like if there was a countdown for when the music changes. I really got into the groove of the music (which slaps so hard btw!) , and the abrupt change in tempo breaks me out of the flow.
Another is, currently players are mainly tasked to do two big things at the same time -( 1) fight NPCs (while maintaining the beat) and (2) "manage" and assign the dice. Can get quite overwhelming, especially with swarms of enemies coming after you. You can consider either separating them into two phases, or maybe having the shooting be automatic (players will then be focused on making music out of the cubes and aiming during attacks).
And an idea - maybe can add different drum parts to different mechanics (bass/kick drum, hi-hat, crash symbals, toms, snare). Would be sooooo cool.
Would love to see more, would pay for the game too ngl!
Cheers mate, keep it up!