What are some alternatives?
When comparing Rocksmith and Incredibox, you can also consider the following products
Frets on Fire - Bonus content.
Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
StepMania - Rhythm game for Windows, Mac, and Linux.
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.
Audiosurf - Audiosurf is a music-adapting puzzle racer where you use your own music to create your own experience.
Bandfuse: Rock Legends - Bandfuse: Rock Legends developed by Realta Entertainment Group and published by Mastiff.