Thank you 8bitpineapple. These are all good observations and I'm impressed that you made it to level 31.
Beyond 160bpm the music feels absurdly rushed so that's where I capped it. After that, the frequency of ghosts increases a bit and the max number of ghosts continues to climb. If this were not a time-limited jam game, I would have liked to add story elements, pickups, extra moves and so on to keep the interest going in different ways.
Good point about the chest. I wanted to keep it recognisably similar to Gauntlet but maybe a coin or a diamond, or even a disco ball would have been better.
The changeover from one tempo to the next is not very smooth anyway. I should see if a fast fade-out will fix it.
Thanks again for all the feedback!