Lumines is perfect for PSP. It's perfect for any handheld game as you can play it for five minutes or five hours. It's simple, yet addictive at the same time. The fact that it's so simple leaves you to plan your moves with the blocks given to you and how fast you go to stack up the combo.
You place 2x2 blocks onto each other and making rectangles with the same colour. The timeline comes along and erases the rectangle giving you points, but you get more if you put on more of the same blocks together. Then there's the special block which when applied makes all adjacent blocks of the same colour erasable, giving you a screen-clearing points-a-thon! This is very satisfying when you look like you're stumped on the game until one of those blocks comes along.
Is it better than Tetris? It feels different yet instantly similar - just falling blocks - but while Tetris just goes faster and faster til your reflexes snap, Lumines changes 'skins' every 5 minutes or so to change the scenery. Different background, different coloured and designed blocks and a different tune. The speed of both the blocks falling and the timeline also differs accordingly to the skins, giving each skin its own feel and strategy. Even if the skins change to the same lineup, it keeps the experience fresh while still being fundamentally the same.
All in all, Lumines is an excellent puzzler, and excellent PSP game, an excellent game full stop. It suits the handheld perfectly and you'll be playing for one more go after every time you beat your own high score. Essential for anyone with a PSP.