Flow is the Playstation 3's answer to Geometry Wars on the X360. However, the gameplay in Flow is vastly dissimilar to what you find in Geometry Wars
The following link is to a flash implementation of Flow. There is even an offline version for you to enjoy at home.
http://intihuatani.usc.edu/cloud/flowing/*edit* While we are talking about the PS3, spotted this HD video (Quicktime) over at Penny-Arcade.