Osu! (stylized as osu!) is a free-to-play rhythm game primarily developed, published, and created by Dean "peppy" Herbert. Inspired by iNiS' rhythm game Osu! Tatakae! Ouendan, it was written in C# on the .NET Framework, and was released for Microsoft Windows on 16 September 2007. The game has throughout the years been ported to macOS, Linux,...