Big Guns
In the Air Base level go to the left and destroy the A-10 plane there by attacking it. A huge gun should fall out, which is heavy for all characters, slowing down their overall speed.
Destroying a car works the same way as destroying the plane from the Air Base level: strike it multiple times until it explodes. If you are using the character Smasher, you can use the engine as a weapon.
Easy Money and Special Moves
Roll into the walls and money will pop out. Roll directly into the walls, not around them. Money allows you to obtain more items and power-ups.
Each character is given special moves, which are listed at the end of its bio. Each character has four special moves at its disposal.
Rocket Launcher
Destroy a police car in the car park level, and a rocket launcher will appear. Rocket launchers fire devastating projectiles but have a short ammunition supply, so use them wisely. Also, watch where you aim them as friends you are playing with can be hit by the rockets as well.
Level Select and Invincibility
Press and hold "L", "Z", "C-Up" and "C-Down" at the main menu. You will be sent to the character select screen where you can use "C-Left" or "C-Right" to choose your level. You are also granted with invincibility upon entering this cheat, which makes you immune to all attacks by all enemies.