This section reveals every known secret in the game. This includes secret levels, secret places, secret messages, secret combinations, and even some "unofficial" secret places. Unofficial secret places are quite hidden but are not counted in the end-level tally. The corresponding map filenames and authors are listed next to the level titles. The level designers are listed according to the signatures in each map. The only exception is Levelord's work in Episode 4, which went uncredited in the official documents. These revised credits are based on his statements and the fact that his signature appears in Critical Mass.
L.A. Meltdown
| Hollywood Holocaust | E1L1.MAP | Allen H Blum III |
| Red Light District | E1L2.MAP | Allen H Blum III |
| Death Row | E1L3.MAP | Allen H Blum III |
| Toxic Dump | E1L4.MAP | Allen H Blum III |
| The Abyss | E1L5.MAP | Richard Bailey Gray (Levelord) |
| Launch Facility | E1L6.MAP | Allen H Blum III |
| Faces of Death (DM) | E1L7.MAP | Allen H Blum III |
| User Map (DM) | E1L8.MAP | Allen H Blum III |
Lunar Apocalypse
| Spaceport | E2L1.MAP | Allen H Blum III |
| Incubator | E2L2.MAP | Richard Bailey Gray (Levelord) |
| Warp Factor | E2L3.MAP | Richard Bailey Gray (Levelord) |
| Fusion Station | E2L4.MAP | Allen H Blum III |
| Occupied Territory | E2L5.MAP | Allen H Blum III |
| Tiberius Station | E2L6.MAP | Allen H Blum III |
| Lunar Reactor | E2L7.MAP | Allen H Blum III |
| Dark Side | E2L8.MAP | Allen H Blum III |
| Overlord | E2L9.MAP | Allen H Blum III |
| Spin Cycle | E2L10.MAP | Richard Bailey Gray (Levelord) |
| Lunatic Fringe | E2L11.MAP | Richard Bailey Gray (Levelord) |
Shrapnel City
| Raw Meat | E3L1.MAP | Richard Bailey Gray (Levelord) |
| Bank Roll | E3L2.MAP | Richard Bailey Gray (Levelord) |
| Flood Zone | E3L3.MAP | Richard Bailey Gray (Levelord) |
| L.A. Rumble | E3L4.MAP | Richard Bailey Gray (Levelord) |
| Movie Set | E3L5.MAP | Richard Bailey Gray (Levelord) |
| Rabid Transit | E3L6.MAP | Richard Bailey Gray (Levelord) |
| Fahrenheit | E3L7.MAP | Richard Bailey Gray (Levelord) |
| Hotel Hell | E3L8.MAP | Richard Bailey Gray (Levelord) |
| Stadium | E3L9.MAP | Allen H Blum III |
| Tier Drops | E3L10.MAP | Richard Bailey Gray (Levelord) |
| Freeway | E3L11.MAP | Allen H Blum III |
The Birth
| It's Impossible | E4L1.MAP | Randall S Pitchfird II |
| Duke-Burger | E4L2.MAP | Allen H Blum III |
| Shop-N-Bag | E4L3.MAP | Richard Bailey Gray (Levelord) / George Broussard |
| Babe Land | E4L4.MAP | Allen H Blum III |
| Pigsty | E4L5.MAP | 99.44% Richard Bailey Gray (Levelord) / 0.66% Randall S Pitchfird II |
| Going Postal | E4L6.MAP | Allen H Blum III |
| XXX-Stacy | E4L7.MAP | Richard Bailey Gray (Levelord) / Keith Schuler |
| Critical Mass | E4L8.MAP | Richard Bailey Gray (Levelord) / Keith Schuler |
| Derelict | E4L9.MAP | Allen H Blum III |
| The Queen | E4L10.MAP | Randall S Pitchfird II |
| Area 51 | E4L11.MAP | Randall S Pitchfird II |