[Key ~eternal tie~]

I've just downloaded this game, there's a variety of songs available initially ranging from themes from Mario, F-Zero, Zelda to jpop classics such as fragile (Every Little Thing), Sakuranbo (Otsuka Ai) and of course, Ayu's SEASONS. It's pretty much like Guitar Heros when you have to press the right keys at the right time.
There's other stuff as well, but I can't read Japanese, so don't really know what it's about.