It does have the third movement. I tried it for shits and giggles:
- Playing fast sections of a song is like mashing through a cutscene, but it's easier to press quickly (not sure at a consistent pace) with multiple fingers. The original piano music was meant for multiple fingers as well.
- The hardest part is advancing the right number of buttons. I don't even know the right number of notes in the trills, and would kinda prefer if the website automatically advanced through trills finer than a 16th note, so it's less likely to end up desynced with the actual piece (I'm not sure if you get used to it with learning each piece or not).
- The website has noticeable audio latency, which makes it hard to associate keypresses and which sound came out in fast sections.