It is kind of short for a real game, but it's still worth it. When you buy it, you'll be laughing.
A down side to this game is that you can only play as three people. Stewie is the one-year-old who has plans for world domination. His enemy is his half-brother, Bertram. Stewie can attack with a ray-gun that can be upgraded by collecting parts. He can charge up his ray-gun to shoot more powerful blasts.
Peter, the "below mentally retarded" father of the family. He gets hit in the head and now believes a 1970s star named Velvedeer has taken his family and the rest of Quahog hostage. As Peter, you must fight over the Police, Indians, and other enemies with his "Fists of Fury." You gain special attacks as you progress. He collects different types of foods for his snack meter. The more special attacks you use, the more snack energy you use up.
Brian, the sophisticated, talking white dog. He has no way of defending himself. Most of his missions are stealth missions. If he is in the shadows, he will be safe unless someone touches him. Brian can collect different costumes to trick all enemies. When he is in a costume, he is safe unless he touches someone. Some costumes cannot automatically trick them. Some costumes, such as bushes, won't work if you're still moving.
If you're looking for a funny and fun game, this is one of the games you should get.