Glad you enjoyed it!
I'll definitely have to experiment with making the beat timings clearer, maybe if the hypothetical second faster square is transparent so it won't clutter up the screen? And I definitely agree that no sounds for hitting the beat was a mistake on my part. The Neon Flames issue definitely should've been caught too, my only excuse is it being the last song I added right before submission, but I can easily remove the first beat in the next update.
As for the girl... I suppose if she were the one on the floor rather than the monkey, it'd be harder to make out the dances? But in reality she's just there to take up the empty space.