Cheat Mode
     Pause  the  game then hit R1, R1, L1, R1, L1, L1, R1, L1, R1, R1,
L1, R1, L1, L1, R1, L1.

Now go to the options menu and the following cheats will be available:

Cheat Win 
Clear Fog of War 
Enable All Levels 
Gimme $10,000 
Player Invulnerable 
Show LZs 
Toggle Unit Spying