Hello there, fellow DJ loop developers! We had a similar theme for our game, though we certainly went in quite a different direction.
Wow, what a cool and unique idea! A mouse-controlled turn-based dungeon crawler rhythm game is an incredible concept to even attempt, and I'd say you manage to do it quite well, too! There is nothing I can criticize about the core idea itself.
However, I personally found the UI to be slightly too overwhelming. The audio track-like movement system is a nice touch, but I feel like the inputs should probably be closer to the general dungeon area of the screen, as I couldn't manage to properly focus on either part very well. I feel like you should maybe lift up the movement UI to the same height as the dungeon gameplay, or it can get very confusing and/or difficult to follow. But there's some genuinely great core ideas here that could be expanded into a full game!