Beatmania is a rhythm game, similar to DDR or Guitar Hero, except that its played on a controller consisting of a keyboard and turntable.
Anyway, Beatmania Flash tries to emulate the game through flash. Because of this, there are some limitations, such as
- slower speed (compared to regular)
- songs play in full, even if you miss keys
However, there are up to 53 (unlocked through play and points), not including bonus songs. Also, scoring is more lenient.
Just start it up, go into Options to config your key layout on your keyboard, and play Standard (tutorial is probably too slow for most people)