Level Select  -  Get into the carnage quicker with this code. At the password screen, enter "G0LVL" followed by the level you desire. (i.e., "G0LVL14" for level 14.) The words "Cheat Enabled" will appear if you did this properly. 

Ultimate Cheat  -  For all weapons, unlimited firepower, invincibility and access to every level, enter the password 1GOTP1NK8C1DBOOTSON. 

Unlock the XR-900 Geopelia  -  Defeat the hidden, 36th, mission in the Mission Simulator with an A. 

Gameshark codes

Infinite Charges 8009a05803e7 
Infinite Flame Fuel 8009a05203e7 
Infinite Health 8009a04003e7 
Infinite Pulse Ammo 8009a04c03e7 
Infinite Shotgun Shells 8009a04a03e7 
Infinite Smartgun Ammo 8009a05403e7 
Rapid Fire 8009a0240001 
Have Flame Thrower 8008f34a0029 
Have Pulse Rifle 8008f3420029 
Have Shotgun 8008f33e0029 
Have Smartgun 8008f3460029 
Infinite Batteries 8009a05a03e7 
Infinite Bullets 8009a04603e7