What is Osu!

osu! is a freeware rhythm game developed and published by Australia-based company Ppy Pty Ltd, created by Dean Herbert also known as peppy. Originally released for Microsoft Windows on September 16, 2007, the game has also been ported to macOS, and Windows Phone. Its game play is based on commercial titles including Osu! Tatakae! Ouendan, Elite Beat Agents, Taiko no Tatsujin, Beatmania IIDX, O2Jam, and DJMax.

About Osu! Tatakae! Ouendan

Osu! Tatakae! Ouendan is a rhythm game for the Nintendo DS. The gameplay consists of only three elements: tapping circles on the touchscreen, dragging a ball across a fixed path and rotating a spinner very fast. All these elements are timed to (covers of) popular Japanese songs. It looks like this on the DS :

Gameplay example of Osu! Tatakae! Ouendan in Nintendo DS

The gameplay circles can be seen on the bottom screen, and the story on the top screen. Each stage is basically a self-contained story about a person in trouble. That is where the Ouendan (Cheer squad) comes in. Through the magical power of male cheerleading, the player have to help the people in trouble.