Stewie Levels
Stewie uses a ray gun and mind control for most of his powers. The key to getting through levels is collecting the ray bolts that power Stewie's gun. If Stewie is too short to reach objects, press and hold "X" to activate mind control on another character like Lois. Lois is controlled with the analog stick and can open windows or doors for Stewie. Tap the "X" button to shoot ray bolts; do not waste them or you may have to restart a level. Use the "B" button to shoot the grappling hook and climb up on different areas. Shoot anything in your path including pets, little kids and people, to get through areas.
Peter Levels
Peter uses hand-to-hand combat to fight enemies. Collect as many foods as possible to fill up the "Snack Meter" and have Peter engage in large attacks. This will cut down on enemy battles and get Peter through levels faster. Use the kick attack on little children. Peter's arms cannot reach them to punch. Hold down and press "B" to perform a leg sweep on enemies. This works for characters like SWAT members and people carrying bags that block their upper body from an attack.
Brian Levels
Unlike the attacks from Stewie and Peter, Brian can only sneak around levels in the game. Use the analog stick to move him around and the "X" button to crawl. Watch for places to hide. This includes behind cabinets, bushes and cars. Look for different costumes to dress up in disguise as. Police officers will not recognize him when he's dressed up. Stay away from things that attract Brian, like fire hydrants, women and potted flowers. These things will fill up his "Bone Meter" and cause him to create attention by dancing, singing or running around. The police will quickly notice and capture him.
Cut-Away Games
React quickly to the games because they last for less than a minute. Be ready to move the analog stick. A lot of the games like "Sky Hook" and "Sexy Party" require you to run or aim at a certain point. Use two hands for the alternate button games. For example, if you have to press "X" and "B" fast, use both pointer fingers on the buttons and you can complete the task faster. Enter the "Special Features" menu in the game to practice the Cut-Away games. After practicing, you can easily beat them during the story mode.