What are some alternatives?
When comparing StepMania and VOEZ, you can also consider the following products
Frets on Fire - Bonus content.
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.
Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
Rocksmith - Rocksmith builds off of the fundamentals of music games like Rock Band and Guitar Hero by offering fundamental lessons in actually playing guitar.
Audiosurf - Audiosurf is a music-adapting puzzle racer where you use your own music to create your own experience.
McOsu - A free open-source circle-clicking rhythm game practice client for osu!