What are some alternatives?
When comparing Frets on Fire and Audiosurf, you can also consider the following products
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.
Rocksmith - Rocksmith builds off of the fundamentals of music games like Rock Band and Guitar Hero by offering fundamental lessons in actually playing guitar.
Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
Guitar Hero Live - Guitar Hero Live is a Single and Multiplayer, Rhythm and Music video game created by FreeStyleGames and published by Activision.
StepMania - Rhythm game for Windows, Mac, and Linux.
PlayStation VR - Discover a new world of unexpected gaming experiences