Island Wars for PSP is similar to a Tower Defense Game. In Invasion mode you control a cannon on a island in the ocean and you are attacked by many different types of enemies. You have to defend your island and shoot down the enemies. But they fly above your palms and destroy them. To prevent this you fire with different types of weapons and shoot your enemies down. In 25 exciting waves in 3 different difficulty you have to prove your skill.

Watch this video on YouTube.

http://wololo.net/talk/viewtopic.php?f=26&t=3901