Yellow Jacket-in the Junkyard level, shoot the plane that circles the area with a Flame or a homing missile. It will start descending and crash into a building. Drive down to the wreckage and drive through the hole in the building. You will see a pillar with a control panel on it. Shoot the panel and you're done.
Axel-in the Freeway level, go down to the construction yard. You will see two cranes. One holding a crate and one holding a pipe. Aim at the control panel on the crane holding the pipe. If you do so, the crate will be lowered. Blow up the crate and you're done.
Manslaughter-in the Prison Passage level, wait until the ship is dockd. Drive down to the bottom of the boat. From the ramp, go right and go to the hull. You will see a stack of crates with a health pick-up on top. Shoot the crates and they will form a ramp. Drive up the ramp and shoot at the side of the boat.Drive into the hole and you will see a pillar with a control panel on it. Shoot the control panel and you're done.
Warthog-in the Suburbs level, go to the Ferris Wheel. Turn around until you see a small hill with a gas can power up. Aim at the pick up and drive. Jump off and you should land on top of the factories. Shoot the raised section. Drop down inside. Shoot the control panel and you're done.
Minion-complete story mode with all characters, including the ones above.
Elevators-in the Highway Loop level, go to the raised bridge and shoot the first round storage container at the chemical plant next to it. It will roll onto the road and eventually make a hole in the tunnel. Get the cube inside to unlock.
Power Plant-in the Junkyard level, shoot the pizza man. His box will form a ramp. Go up it and wait until the trash compactor is raised. Jump onto the building. Collect the cube and you're done.
Hint #1: When on the Skyscrapers Level, try to stay on one building, so you don't fall off.
Hint #2: When Fighting Minion, run away from him so that you get far away from him, when you're on the other side of the stadium, start firing your guns until his field is damaged, then hit him with fire missles and homing missles.
Hint #3: When fighting WarHawk, stay far away from him. When you are far away from him, use homing missles and guns to kill his field, then use homing missles
If you are new to the game heres the way to unlock YellowJacket. Theres a plane flying around the area. Fire two fire missiles at it and the plane should fall in the pit like area go there and there should be a tunnel go through it (its a pretty long way). There should be a big thing in the middle of the room find the yellow box and blow it up and you have YellowJacket!!!
This isn't really a walkthrough, just something that I had the time to do. When you play as Minion, he speaks in a number code. I have cracked that code, and this is what he is saying, level for level.
Level 1: I do not think this is real.
Level 2: I must speak in code or he will discover me.
Level 3: We are trapped in his head.
Level 4: This is how he sees the world, how Sweet Tooth see's his life. It is not real.
Level 5: All of us are trapped in his head.
Level 6: I miss the old colorful world.
Level 7: We will return to our old world one day.
Level 8: In the real world my name is Marcus Kane.