In the Junkyard level, there is a big fat pizza man hanging. Blow him up with a couple of gas cans. After he is blown up, the debris will leave a ramp to jump onto the trash compactor. Ride it all the way up and drive on the the little platform. Turn around and face the trash compactor and there is a black box to the left. Jump off of the little platform to get it. It will unlock a new level for two player modes.
Energy Attack List
The following commands need to be entered while playing:
Granted effect - Command
Freeze Ball - Up, Down, Up
Mine - Right, Left, Down
Charge-Up Mine - Right, Left, Down (hold down for one second)
Invisibility - Left, Left, Down, Down
Shield - Right, Right, Down, Down
Jump - L1 + R1 Simultaneously
Rear-Fire Weapon - Left, Right, Down + weapon fire button
Freeze Special Attack
Hold L1 + R1 + L2 + R2 and quickly press Right, Left, Up during game play. A message will confirm correct code entry.
God Mode
During gameplay press and hold R1, R2, L1, L2 and then press Up, X, Left and Circle.
Infinite Ammo
To get infinite ammo, during any time of the game hold R1+ R2 + L1 + L2 and then press Up, X, Left, Circle.
Invincibility
While playing, hold L1 + L2 + R1 + R2, Press Up, Down, Left, Right, Right, Left, Down and Up.
Invulnerability on
During gameplay, press and hold R1, R2, L1, L2 and then press Right, Left, Down and Up.
Mega Guns on
During gameplay press and hold R1, R2, L1, L2 and then press X, X and Triangle.
Multiplay level: Downtown
At the Downtown level, locate the set of buildings connected at the second story on one side of the river/bayou. You can find it easily when you drive between them, since there is a big section of wall that is very visible that you can shoot out to get to the elevators. There is one on each building. When facing the buildings from the river, take the left-hand elevator up. Then, circle around to the back of the building. Along the way you will notice that the ground changes color. About one car length to the left of that line is where you want to creep to the edge and barely fall off. You should hit the cube while falling. If not, you should be on a different level off of the ground -- jump (press L1 + R1) to get the cube. It can be seen from the ground floor once you know where to look. The Cube get's Minion's Stadium level in Mulitplayer mode.
Multiplay level: Highway Loop
Go the Highway Loop Level and kill off about six to seven of the combatants. Drive to the raised, broken bridge (with the two health pick-ups and another pick-up in between), and find what looks like a power plant, directly off the road. There are about two to three giant steel balls there. Shoot the one closest to the bridge with a Gas Can (the projectiles don't work well for this), and it will break off and start rolling. Make sure to stay clear of its path, or you'll be squashed. Follow the ball and when it crashed through a wall, follow into the newly opened area and find the Black Cube inside. Health and weapon pick-ups are also inside. Black Cube opens Elevators Level in multiplayer.
Multiplay level: Open Mini-Suburbs
To open the Mini-Suburbs for multiplayer action, get 10 Kills in Survival Mode in the Drive-In arena.
Multiplay level: Skyscrapers
When you're at the lower Repair Station and you want to drive to the hollowed airplane tunnel, shoot the billboard or ramp into one of its posts to knock it down. In that gap to the right between the buildings is a Black Cube; you can get it, but it will cost you a life -- it opens up Sewers level in Multiplayer mode.
Multiplay level: Snowy Roads
Go to the spot in the level with an open lot with a gas station. Go to the edge of the cliff there and you'll see it floating there. Just drive over carefully and grab it. Cube = PowerPlant.
One Hit Kills
During gameplay, press and hold L1 + R1 + L2 + R2 and quickly press X twice, and Up during game play. At the top of the screen a message will confirm you've done it right.
Skyscrapers
When you're at the lower Repair Station and you want to drive to the hollowed airplane tunnel, shoot the billboard or ramp into one of its posts to knock it down. In that gap to the right between the buildings is a Black Cube; you can get it, but it will cost you a life -- it opens up Sewers level in Multiplayer mode.
Super Machine Guns
To get super machineguns, during any time of the game hold R1+ R2 + L1+ L2 and then press X, X, Triangle.
Tips For Defeating Minion
Minion is a very tough half-way boss. His attacks on you that he blows are unflawless, and he can very easily take you out in a few hits. The way the game says to kill him is by shooting his front and back panels, which eventually destroy the force shield, but it takes good aiming and a lot of work. I found the easy way to defeat Minion. When you start at the very beginning of this "Level" he is far away from you and he begins charging very fast. You should be already equipped with some weapons, including your special. Turn, and look straight at him as if you are going to collide head on, aim, and shoot your special, and if it hits the very front if him, Minion will be bown to pieces in one shot.
Unlimited health and turbos
Hold L1 + R1 + L2 + R2 and quickly press Right, Left, Down, Up during game play. A message will confirm correct code entry.
Unlock Axel
In the Freeway level (not the Highway loop) grab a few fire missiles and head off to the construction yard you should see two cranes. One to the left and one to the right your target is the one to the right. You will see a Control cage hanging in the middle of the crane all you need to do is hit this once with a missile. The best way to do this is angle yourself driving at the hill with a straight line between you and the Control Cage. Hit a turbo and launch off the hill. While in the air launch a missile. If done correctly the missile will hit the cage and cause the crane to lower a box. Drive over to the box and shoot it until it opens and gives you Axel. This one may take a few tries to get it is the most difficult character to unlock.
Unlock Manslaughter
In the Prison Boat stage once the boat docks and you can go onto dry land, Drive down to the front of the boat on the dock. If you are facing the front of the boat (the prison entrance should be behind you) drive to the left of the boat, you will see some blue crates and a health pack on top of the crates. Fire a missile at the crate on the left and it will break in half forming a ramp. Drive up the ramp and shot at the hull of the boat in front of you. After a moment of fire it will open and you can drive inside the boat. You will see a control panel, blast it to unlock Manslaughter.
Unlock Minion
Beat the game with every character, including hidden characters, to unlock Minion.
Unlock Warthog
In the Suburbs head up to the Ferris wheel. (say you are facing the Ferris wheel head on from the front) drive off to the left, you'll run over trailers and see a hill in front of you and a gas can on the hill aim for this and launch off of that hill. Try to land on the first building in front of you. If you land just right you could break open the roof and fall in but if not you should be able to use the gas can to blow open the top right hand corner (that direction is based on you looking at the building while on route to it off the hill) it should blow a hole thru the roof....drop down in there and shoot the panel to lower Warthog (formerly called White Knight).
Unlock Yellow Jacket
He is found in the Junkyard Level. You will see a plane flying in the background, you need to shoot this down with a missile. The easiest way to do this is get onto the roof of the Incinerator (the round building with ricochets on top and flames on the sides). As the plane flies by to the left (the left if you are facing the elevator/crushing thing) shoot homing misled a little in front of the plane to knock it down. Once the plane falls go down into the pit near the environment trigger (the gun on the wreckage) the plane will have crashed into he side of a building down there and a hole will open up. drive down it and collect the weapons. At the bottom there is a control panel, shoot it and it will lower Yellow Jacket.
Weapons for health
Hold L1 + R1 + L2 + R2 and quickly press Triangle, X, Square, Circle. During game play. A message will confirm correct code entry.