What is osu!?
osu! is a rhythm game based on the gameplay of a variety of popular commercial rhythm games. While aiming to keep authentic gameplay and scoring, osu! increases the epic factor through online rankings, multiplayer, replay exchange, and a huge community following. Also available is a fully functional built-in editor, allowing intuitive creation of your own beatmaps for the songs you want to play.
Gameplay is very similar to Ouedan/Elite Beat Agent series on NDS with online ranking system and CO-OP Play. Only inconvinence is that you have to use a mouse/keyboard to play through. Maybe they will support Windows 7 and touch screen monitor in future? IDK.
It's awesome to play Osu! because I can download beatmaps of songs that I like and they give a better sense of rhythm than some other games (such as audiosurf).
But it's not so awesome to play with the mouse (unless you have a tablet PC) because it's ultra difficult and I get the worse arm/ shoulder cramps afterwards.
actually, if you do digital drawings like me, using tablet is actually much more easier, and you dont even have to look at your tablet to play properly. tablet users are used to it :3
but hey, everyone has their own play style and preference, so idk :3