After you install version 2.7 of the PSP firmware, head over and download the demo of LocoRoco. This is a Japanese demo of a game published by Sony, and should be played by all. It has that simple puzzle game addictiveness. I only wish there was an English version publicly available.
Using the L and R triggers, you tilt the screen left and right. Use the X and Circle buttons subdivide and group your little yellow LocoRoco. Holding and releasing L and R will allow you to hop.
You navigate through levels eating fruit to grow, and break into smaller pieces to make it through smaller gaps. You use the environment to do all the work. Tilting the playfield, speeding up and slowing down the LocoRoco to make large and small jumps to get over obstacles, jumping out of the way of baddies, and passing through puzzles is all you will be doing.
But that is all this satisfying demo needs. It has a very Katamari Damacy feel to it. The game is vibrant with color and fun music. Life as a yellow blob is good. This will surely be a smash hit when it hits store shelves, which is yet to be determined for the US. I am hooked, and cannot wait for more LocoRoco.