Lot of potential here. Only 2 real complaints here:
The minigame, mentioned by many, needs some work. I like the idea of a rhythm game, that's one of my favorite types of minigames, but it needs to sync with the music, and have a better indicator of what key to hit and when. Either come up with a way to make the arrows easier to see, or just go with a DDR style where they come down a lane.
Other thing, I'd love to see some voice acting in this. Even if only some stock moaning or something. Just, seeing somebody silently getting fucked is a bit.... underwhelming.