This is a total classic. Based on lemmings' strange tendancy to commit suicide, the game is about trying to save a few dozen small people in blue from falling to their deaths, drowning, being crushed or being blown up, and getting to the target end door. You do this in a variety of easy ways. You have a limited number of uses of these tools, and so have to work out the puzzle and what the level is trying to make you do. You select the tool then click the lemming/person/thing and that lemming/person/thing then does what ever you have selected, such as digging, blocking other lemmings from passing, tunnelling, building steps, or can then do something, such as use an umbrella to slow down a fall so they don't get squished. There are a variety of different difficulties and all the levels are different, so you do not get bored easily.

However, PSP games do not come cheap, so unless you are buying them second-hand, I don't feel the price is worth the game, especially when I know that on PC the game is much cheaper and also easier to play, as the game requires a lot of selecting with a pointer, and so this naturally is easier to do with a mouse, no matter how dextrous you are on the PSP. The game was also designed ages before the PSP was even thought of, so obviously the game is not entirely adapted to the PSP.

So, the actual game is worth it, but I would suggest getting it for the PC instead, and spending money on a game more suited to a PSP.