What are some alternatives?
When comparing Clone Hero and DittoBeat, you can also consider the following products
StepMania - Rhythm game for Windows, Mac, and Linux.
Frets on Fire - Bonus content.
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.
VOEZ - VOEZ invites you to embark on the remarkable journey of teenage dreams
BeatX - BeatX is a Stepmania/DDR for Android