Just like the title says. It is similar to GH. Except you dont need a guitar. I always have a great time whilst playing this game. I do agree with others that some songs go to the beat while others just kind of...go. If you dont have a guitar and need something rated G, this will work.
I literally played this game 15 minutes after the waiting through the long beginning. I thought it would be fun playing story mode but all it did was make me sit and shake the Wii remote and nunchuck to different beats in the song. I didn't do well because if you shook the remote to hard it destroyed the stars behind it which gave me a worse score.
I don't know who thought story mode meant going through songs and sitting there shaking a remote without an actually story but they should be fired.
All in all I would say don't waste your time with this game or take up space in your game Q it isn't worth it.