Successfully complete the game with all secret and speed chips to unlock General Corrosive as a playable character in multi-player mode.
Successfully complete campaign mode to unlock the Original Concept FMV sequence.
In any multi-player level, press Start. You can be shot at, but receive no damage. You cannot move, but it is better than dying.
When playing in the coliseum, you will fight against General Corrosive in the last match. You cannot hurt him. When you enter the arena, run to the far right side. There is a box that has a health in it. Hide on the side opposite General Corrosive and get him to destroy it with a rocket. When he does, get the health. There is also a wrench when you get the health. Run from the general and hide in one of the small huts. When inside, quickly disassemble yourself. The general will destroy the hut and find you in pieces. A short intermission sequence will play and you will proceed to the next level.
In last level, you will find yourself in ruins of the Space Station that you destroyed earlier. After General Corrosive survives the crash, he will get very mad, but will not be that "indestructible". First, try to shoot off his right leg so he will not be that fast. Then, go for his left arm that he uses to get those flying green things out of his mouth. Next, go for the whole thing. It will be easy with rockets and few "cleaners".
Fire missiles at Kingbot until he stops moving. This usually happens after about four to five shots. Then, aim your targets at his right leg, stand just off-center, and throw in a Core Charge. This normally takes about five times. After ever two charges, some little bots will appear. The best weapon to use against them is the Scatter Ammo, as it will kill them quickly, especially when they are directly bearing down on you. Missiles will cause more damage to your health. Additionally, disable the King Bot by firing missiles at him. This will make him stop in his tracks. Then his mouth will open, and you can throw core charges in. Next, aim your recticle (target) at his leg where it meets his body. You need to stand slightly to the right.
In the Fire It Up level, there are a lot of Swarmers (the little spiders). Use the flamethrower to temporarily push them away. If there are a large number of them, the easiest way to kill them is to double jump over or out of them. If they start eating at your joints, double jump and they should get off.
Reach the part of the They Live level where two zombie bots are trapped in two cages. Free them by cutting the red wires that are holding the cages and they will become your allies.