So I take it the game has at least sold more than 500 copies at non-Wal-Mart retailers, eh? Better than SpyBorgs!
Also...
The music-game genre isn't really one that can be over-saturated. The more experience developers get adding in gameplay to songs, the more programs are written, the more possible it is to create songs for cheap that can sell in insignificant numbers. All it means is that it's a market that will always be able to consistently make money, and we've reached that point. Personally, I don't see a huge problem with it. We're taking up talent from Activision, a developer with very little unique and original IP, and Harmonix, another developer who's sole purpose has been to create music games on a level like this.
The reason it'll last is that people have enjoyed creating, playing, and listening to music for at least thousands of years. This is just another opportunity to do the same.