I was very hesitant I was going to like Pixeljunk's Monster Deluxe on the PSP. It is very fun, and simple. I think this is really a good example of how Mini games should be. Its really entertaining and very addicting when you start learning on how to play.
The main object of the game is to protect flocks, which are the little creatures that appear near the base (the round house type looking thing). You will have many types of monster trying to kill the flocks. Your job is to prevent that from happening by creating towers that will automatically shoot them. Some monsters have tough skin though and do not die easily. The towers come in different types, some are better to effectively kill some monsters. Just think strategy!x3...lol. You earn, collect money when monsters are killed (and sometimes find money on trees) and gems for the development of better type towers, and upgrading them. A round comes to a conclusion when the enemy boss shows up. he should be the hardest of all to kill, but with all the help from your powerful towers, he do not stand a chance (See the video above):D
I just got so much into this game, I could not put it down. You just gotta experience for yourself for sure.