Fat Princess

The Legend of the Fat Princess, for Playstation 3, is a wonderful multiplayer game along the lines of "Capture the Flag".  Only the flags are the opposing teams' princesses.  You have to build and defend your own castle, upgrade characters, and stuff the princess so full of cake she turns into a giant blob (which in turn makes it very difficult for the oppostion to steal her back, as they must carry her).

(The pic is of my Ranger character after stuffing her with lots of cake)

There are 6 distinct types of characters in the game: a villager, worker, ranger, mage, warrior, and a priest.  Everyone starts as a villager and is very weak but can slap others to make them drop things and have a chance to daze them.  As soon as you pick up a hat from either a dispencer in your castle or on the battlefield after someone drops one upon their death, you gain the abilities of that character type. 

Each of the other classes has 2 levels.

• The worker is quick and can mine metals and chop down trees to help build and upgrade things.  They begin with more life than a villager and have an axe to defend themselves.  The 2nd level is a Bomb thrower.  These little guys are very dangerous, they can blast the hell out of everything in sight.
• Rangers start as distance fighters with a bow and arrows.  Their upgrade gives them a slower but more powerful weapon, a blunderbuss.  Very fun medium ranged character, medium life bar, medium attack power, and fun for beginners. 
• Mages start as fire users, sending out blasts of fiery death, and once upgraded they can use ice to slow, freeze, and damage enemies.  Unless you are with a group, these guys can be slaughtered quite quickly.  A side benefit with this upgrade is a magic potion dispencer starts giving out a bottle that if thrown on enemies(or dropped on yourself) will turn anyone in blast proximity into a chicken.  Chickens have the least amount of life, but are fun to run around jumping, pecking and squawking as. 
• A warrior begins as a simple, strong fighter with sword and sheild.  Their upgrade provides a huge attack bonus with a large spear and a charging slash, as well as a life bar boost.  They have the most life and are fairly difficult to kill.
• Finally, the priests.  They are originally healers, being able to heal, and eventually upgrade to dark priests, able to drain the life force of enemies in the nearby vicinity.  Very helpful for friends, but choose to be them only if you have lots of backup.  They don't stand much of a chance out on the battlegrounds on their own.

The game itself has both Single Player and Multiplayer options.  In Single, you can learn the Legend of the Fat Princess, by playing through a series of story based games, all based on parts of the whole Multiplayer game, such as killing the opposing teams entire group (Team Deathmatch).  The second Singleplayer mode is a gladiator arena where the player must defeat wave after wave of enemies in a stadium.
Multiplayer Mode: This is where the game is really amazing- teams of up to 16 versus 16 people in the capture the princess or team deathmatch modes.  Unbelieveable amounts of death, in your choice of either bloody gore, or my own choice the, inexplicably more disturbing, "Clean" fights.  With this setting every enemy defeated explodes into a mess of teddy bear parts, confetti, toys and various candies like lollipops.  This is hours of insanely fun entertainment.

I highly recommend this game.