Geometry Wars: Retro Evolved is a great arcade game. It's great to just pick up and play, but it's not easy, and you will enjoy improving your high score. Will it hold your attention?
This is a fun but ultimately limiting game. It doesn't offer progression, meaning you're playing the same level over and over, and the music gets repetitive, because it's a very short tune that loops. It loops well, but it's just one short tune.
The Xbox 360 version has achievements to give you more reason to keep playing, however, the achievements are probably too difficult for most people. Overall, the best version of the game is on PC, but if you're truly interested, you should get the sequel, Geometry Wars: Retro Evolved 2.