Cute and simple. I like how this plays like a Rhythm Heaven remix level, shifting between different "mini-games" with a simple control scheme. The game was synced for me as well. No input/audio delay.
I initially tried this on Firefox and was met with terrible hiccups (no pun intended) making it impossible to play properly. I thankfully tried Chrome and it worked just fine. I do hope this get ironed out for other browsers at some point. If not, I won't mind opening Chrome again for this :V