Metal Arms: Glitch In The System Cheats for PlayStation 2

This robot boss which is a failed science experiment by Chief Scientist Dr. Exavolt becomes available in Multi-Player mode when you complete the game with ALL Secret and Speed chips.

Ok, so when you are in the 1st wasteland level when you reach a place where in the distance you can see 2 cages with zombiebots in it first kill the 2 zombies that try to attack you.
Then using the ripper cut down the cages with the zombies in it and they will rush to help you kill all the enemies that dare defy you hope this helps and sorry if it is a bit confusing.

To unlock the Concept Movie feature beat Story mode.