The Disgaea series has done well enough in Japan that it was only a matter of time before a spin-off was developed for its most popular in-game mascots, the Prinnies. The game's story is based around an army of 1,000 Prinnies (which, consequently, gives you the same amount of lives in the game) who must find ingredients for an Ultra Dessert, or else the demon lord Etna kills them off one by one.
FUN FACT: A sequel was released in Japan in early 2010 called Prinny 2: Dawn of Operation Panties, Dood!. No, seriously. The American version actually just launched this month on PSN.