Here are some ideas
The graphics to me aren't sitting well together, somethings are drawn some are low quality textures while others are high quality. they just don't match up right. like the windows look somewhat real and the bricks don't
Consistancy is key! Maybe do some sequencing like more than one mouse command per black out. and you have to do it in the right order.
Also make it so a certain beat or something doesn't play until you hit the buttons
so you need to hit them intime to make the music sound good and right.
battles would be cool too, like doing the certain clicks to kill the beast on your run.
that's all i can think of now =]