Tommy's father, Stu Pickles, invents what he calls the Playpalace 3000, which is a giant expanding tower filled with rooms for the children to play in. Stu leaves to go buy the finishing touches, duct tape and paperclips, and asks Lou to watch the kids. As always, Lou falls asleep. The babies begin to play on the Playpalace 3000, but Kimi notices that Angelica is at the top of the tower. Angelica assumes control of the backyard as queen, and forces the babies to obey her, stealing all of their toys in the process.
Tommy, Chuckie, Phil, Lil, and Kimi are playable characters. Games can be found in each zone, and if the player earns enough big batteries, a new zone will be made available. The player can earn "Funny Money" in the games to purchase mini-games.