Twisted Metal: Head-On cheats and cheat codes for Sony PSP

Single player mode cheats:
During game play, type the following codes bellow. 
To disable the cheat, type them again.

Unlock Killer weapons: Press X(2), Up(2), L + R 
Unlock Invincibility: Press Right, Left, Down, Up, L + R 
Unlock Infinite weapons: Press Triangle(2), Down(2), L + R
Unlock Mega guns: Press X, Triangle, X, Triangle, L + R
Weapons health: Press Triangle, X, Square, Circle, L + R
Unlock Temporary shield: Press Right(2), Down(2) 
Unlock Temporary invisibility: Press Left(2), Down(2), N
Mine: Press Right, Left, Down, Up
Unlocked primed: Press Up, X, Up, X, L + R


Story mode unlockables:
Unlock Axel: Finish the Russia mini-game
Unlock Mr. Slam: Finish the L.A. mini-game
Unlock Crimson Fury: Finish the Monaco mini-game
Unlock Hammerhead: Finish the Tokyo Rooftop mini-game

Greece Deathmatch level: Finish the Greece mini-game 
Egypt Deathmatch level: Finish the Egypt mini-game 
Paris Deathmatch level: Finish the Paris mini-game 
Rome Deathmatch level: Finish the Rome mini-game 
Tokyo Streets Deathmatch level: Finish the Tokyo Streets mini-game 

Unlock Dark Tooth: Finish story mode in single player mode 

Unlock Tower Tooth: Finish the game in story mode with any 5 characters
Unlock Tower Tooth Challenge level: Finish the game with any 4 characters
Unlock Cousin Eddy and ATV: Finish the L.A. Cousin Eddy mini-game

Re-watch ending movies:
Go to the options menu to replay the ending movies.

Tricky way to kill the enemy:
Place a remote bomb on any teleporter.  When somebody teleports, 
the remote bomb will explode.