Sony has said that PSP game Fat Princess:
Fistful of Cake will support up to eight players locally or online.
There are other extras too, such as six new levels spanning unseen environments like forests and volcanoes, and an expanded story that covers the fate of greedy fat-fingers herself. On top of that are added multiplayer modes Dilapidated, Grim Ripper, Demolition and Jailbreak.
But otherwise the concoction retains the zesty punch of the PS3 game, where teams of four duke it out in a medieval cartoon royal-rumble to capture the fat princess, who's been smashing cake into her blubbery mouth.

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Fat Princess is one of the PS3's best and pretty soon, it will also become one of the PSP's best.
The game that got some over-sensitive feminists a bit miffed - can't satisfy 'em when the women in games are too thin; can't satisfy 'em when they're fat...big damn surprise - is going portable, and according to Joystiq, Sony says it'll boast "50% more content" on the PSP. Apparently, this is due to the addition of all-new game modes that weren't featured in the PS3 version, "including one where the class hat generators are busted at the beginning of the match and must be repaired using resources before they can be used." Then there's another mode where the Princess is non-existent and players are focusing on something a bit more deadly: a bomb. You have to deliver it to the opposing teams' castle (and there may be a time limit, so if you can't make it, the thing blows up in your castle). In the end, Sony is calling Fat Princess PSP "Fat Princess 1.5," as it also has "an expanded single-player component, a new map and the aforementioned new modes." Maybe this is why it has a brand new title on the PSP: Fat Princess: Fistful of Cake. Or, maybe it's just because there will be more...um...fistfuls of cake.
There is no official release date attached to this handheld iteration just yet, but we assume it'll be ready to go before the end of the year.