The game is split into 22 levels for the three playable characters: Peter, Stewie or Brian. Peter and Stewie have eight levels, while Brian has six. Each character has his own unique style of play.
Some other characters can also be controlled by the player during small fractions of Stewie's levels, as he possesses a Mind Controller Device. These include Lois, Quagmire, Cleveland, Death and Meg, as well as other minor characters and unknown characters.
Peter's levels have a beat 'em up style, similar to Final Fight, Streets of Rage and Double Dragon. In Peter's levels, the player rampages across a section of town, attacking anyone and anything in his path. In addition, depending on the player's progression through the game, Peter will adopt a different persona as a result of head trauma, giving his attacks different animations but otherwise similar results. Peter's alter egos are Rufus Griffin, Hooker Peter and A.N.N.A. (Automaton Nuclear Neo-human Android), played in that order. Peter begins and ends the game as himself.
Stewie's levels resemble a shoot 'em up like Galaga or Space Invaders, but also with similarities to games like the Futurama video game. Stewie uses his upgradeable laser gun and conveniently placed "sky hooks" to move through various stages. He also uses his Mind Controller Device to briefly control other characters and use their abilities, most notably Death, Quagmire and Lois.
Brian's levels have more in common with stealth games like Metal Gear Solid and Tom Clancy's Splinter Cell. Brian must avoid detection by those around him, and can adopt disguises to fool onlookers. A secondary element in Brian's levels is avoiding his natural urge to urinate on things. Should the player remain near certain objects for too long (potted plants, fire hydrants, etc.), Brian will be forced to pee on them, exposing himself to those around him.
Out of the Mind-Controllable characters, Lois has the ability to interact with household items such as the Oven and the Vacuum Cleaner, and she is also the only character that can open the doors inside the family's house. Quagmire and Meg work as Repellents for female and male NPC's, respectively, and can force them to do certain things through their repulsiveness. Death can kill other NPC's and is immune to their attacks. The other characters have no special abilities.
Chris is the only character of the main cast of the show that is not playable in any way through the entire game (Not even through Stewie's mind control), although he appears as a NPC.
A key feature of the game are mini-games done in the same style as the cutaway gags that the show is famous for, usually lasting less than 10 seconds. The mini-games often repeat cutaway gags from the episodes, such as Peter inexplicably burning his hand in a waffle iron. Successfully completing the mini-game offers a bonus: Brian becomes invisible for a short period, while Peter and Stewie receive power-ups for their respective abilities. Lois and Meg are not benefited by any mini-game.
