Fat Princess should be, by all accounts, the PlayStation Network's own Castle Crashers. It's cartoon style is accessible to all, but is full of bloody mayhem. The class system holds an incredible amount of depth and proper teamwork goes a long way. Putting 32 players on a peer-to-peer connection with voice chat is nice, too.
For those that don't know, Fat Princess is a 16-on-16 class-based multiplayer game (though bots are available) that tasks players with rescuing their princess from the enemy dungeon. The five classes are: worker, warrior, archer, mage, and priest. Workers are the key to getting the advantage as they can collect resources to upgrade the "hat machines" that allow players to choose their class.
As you fight to the doors of the enemy castle, you'll gain points for kills and fight to control towers which can be occupied by friendly archers to gain a height advantage on the battlefield. If you die, a short respawn timer sets you back a few seconds, allowing the winning force to advance their position.
Mixing the classes is the key to victory. My favorite strategy was to grab the warrior hat and head to the front lines with the sword and shield. By holding L1, I could raise my shield and deflect enemy arrows and magic. By standing in front of allied archers and mages, I could keep them safe while they launched missiles of their own. I was still vulnerable from the sides, but could usually stay alive long enough to wait for reinforcements.
The worker gets an ax that can be used to chop down trees or enemies. By chopping down trees or ore the worker can collect resources. The mage can shoot fireballs or release an area-of-effect attack that sets enemies on fire. The archer can charge up arrows for a highly-damaging ranged attack. Finally, the priest can heal allies by locking onto them and healing them over time. Additionally, he can charge up an area-of-effect heal to mend multiple allies at once.
Each class gains a new weapon or ability when upgraded. The mage gains ice attacks that can freeze enemies. The worker gets grenades that do area-of-effect damage. The warrior gets a halberd with a charge up attack capable of one-shotting certain classes if fully powered. The archer gets a blunderbuss (shotgun) that hits multiple targets and the priest gets an offensive ability to make enemies take more damage.
The combat plays out very quickly, but there is time to use tactics and strategies. Another neat trick was picking up the hats of dispatched enemies to change classes in the field. Using teamwork, you'll hopefully make it to the enemies door, you'll need to break them down. This takes a while and you'll need a lot of help, especially from priests. Once the doors are down, it's time to get to the dungeon and rescue your princess. If the enemy has been feeding her desserts, she'll be... ahem... fat. It will take more allies to carry her in this case. You win when you bring your princess back to the castle while still holding the enemy princess.
Although I only got to play against bots here at GDC, I had so much fun playing Fat Princess. The AI had a few odd tendencies and I was able to easily exploit the shield with the warrior class. The AI won't flank around at all. The combination of resource gathering, combat, and class-based teamwork is sure to make Titan Studios' Fat Princess a hit when it releases this Spring.