Eradicator

Enter these codes during gameplay:
\RAGAMUFFIN: Invincibility
\BLOAD: Load a specific level
\VICI: Complete the current level
\FMK: Full health
\GIFT: Get all inventory items
\ARMS: Get all ammo
\OVERDRIVE: Power-up microchip
\SPUTNIK: Full map
\AMOBJECT: Show objects in the automap
\GOBBET: Gib yourself
\AIMOVE: Toggle enemy AI
\DIG: Clipping on/off
\FRAME: Display frame rate

Extreme Assault

At the main menu, type ohdear to enable cheats. Hold down ALT and hit these number keys during gameplay to cheat:
1: full ammo
2: weapon upgrade
4: god mode
6: end mission
7: deactivate enemies
8: change to helicopter mode
9: change to tank mode
10: speed boost