All cheats should be entered while the game is paused.

Invincibility :
Down, L2, Square, R1, Right, L1, Left, Circle.

Map with objects :
Triangle, Triangle, L2, R2, L2, R2, R1, Circle.

Level Warp :
Right, Left, R2, R1, Triangle, L1, Circle, X.

Full weapons / ammo :
X, Triangle, L1, Up, Down, R2, Left, Left.

X-Ray Vision :
L1, R2, L2, R1, Right, Triangle, X, Right.

Master Level Codes:
Level 2 - LB173PPWPM - Virgil -
Level 3 - ZSNDHQW820 - Canyon -
Level 4 - KS5WZH4RKH - Combine -
Level 5 - J!670JKQJG - Catwalk -
Level 6 - 5VJTM00W64 - Fistula -
Level 7 - 4FHDW39X35 - Geryon -
Level 8 - W9NRG2W820 - Minos -
Level 9 - C958ZKCRKH - Nessus -
Level 10 - W!PQH1V71Z - Paradox -
Level 11 - C!670JBQJG - Subspace-
Level 12 - W7LTJOY!02 - Subterra-
Level 13 - K394TB8MFC - Vesperas-

TNT Level Codes:
Level 14 - Y8PQH1V71Z - System Control -
Level 15 - F8670JBQJG - Human Barbeque -
Level 16 - WXJCL68W64 - Wormhole -
Level 17 - CX1W3PRCPM - Crater -
Level 18 - WYKBM57V53 - Nukage Processing -
Level 19 - CY2V4NQBNL - Deepest Reaches -
Level 20 - WVGFN4!Y46 - Processing Area -
Level 21 - CVZY5MTFMP - Lunar Mining -
Level 22 - WWHDP39X35 - Quarry -
Level 23 - CW0X6LSDLN - Ballistyx -
Level 24 - W1DHQ!40!8 - Heck -

Plutonia Level Codes:
Level 25 - !LQP7W26WY - Congo -
Level 26 - W2FGR93Z97 - Aztec -
Level 27 - C2YZ8SLGSQ - Ghost Town -
Level 28 - WZBKS8628! - Baron's Lair -
Level 29 - HXZY5MMFMP - The Death Domain -
Level 30 - 0YHDP33X35 - Onslaught -