Definitely a lot more fun playing with friends. A compelling story paired with fun gameplay.
Story: There are two stories that you can follow. To avoid spoilers, I will not disclose information about them.
Graphics and Mechanics: The gameplay is set from a birds-eye view, and the environments aren't very detailed. GSpot's review calls the environments "claustrophobic", which I did not feel at all while playing this game. The cutscenes do look nice, but a bit grainy.
Gameplay: Not too shabby. A leveling up system is used, and points are given to upgrade your respective character's powers. However, while you are playing you are going to find yourself pressing the same button over and over just to get a bit of damage on an enemy. A crucial part of the gameplay are fusion attacks, where your team perform effective moves that inflict massive damage.
Camera: OK at times, dreadful at others.
Overall:
Decent game, but a much better game when played with a friend or two (or three). Forgetting about the technical and mechanical downfalls of the game is the key to enjoying it.