Duke Nukem: Total Meltdown

It's Duke Nukem 3D with an exclusive episode and lots of slowdown.

Unused/Leftover Text
Using a hex editor, you can find many pieces of text that are unused.

Debug

 * DUKE
 * Setting Baud&Packetsize
 * Raise RTS
 * Waiting for
 * CTS
 * Drop RTS
 * Kickstart read
 * synchronous write TM
 * synchronous write failed
 * start async read TMR
 * asyn read error
 * SIO handshake complete
 * DUKEBOT
 * sio:

Map / Multiplayer error messages

 * unexpected packettype
 * You cannot play Duke with different versions.
 * Too many moving sectors at (%ld,%ld).
 * WAITING FOR PLAYERS
 * Duke Nukem 3D(tm) Copyright 1989, 1996 Todd Replogle and 3D Realms Entertainment
 * I want to make a game with trees
 * 16 Possible Dukes
 * Waiting for master to select level
 * Too many switches (64 max).
 * Map %s not found!

PC version multiplayer menu

 * COOPERATIVE PLAY
 * DUKEMATCH, NO SPAWN
 * DUKEMATCH, SPAWN
 * ON
 * OFF
 * GAME TYPE
 * LEVEL
 * START GAME

Labels

 * DAMN I'M GOOD: The fourth skill level is not avaiable in this version.
 * BUTT KICKING ZONE: Name for the episode that contains the multiplayer levels. It cannot be seen during normal gameplay since the automap is replaced with a pause button.
 * BLANK: Unused level.

Messages
These are messages meant to be displayed in-game. The first one is just a hyphen, replacing the "AUTO AIMING" message from the PC version. The rest are rewritten messages from the PC version.
 * GIMME A CHEAT CODE...
 * 
 * 
 * 
 * YOU CANNOT QUICKSAVE WHEN DEAD
 * GOT ALL WEAPONS AND AMMO
 * <012345678901234567890123456789012345678901234567890123456789>
 * <012345678901234567890123456789012345678901234567890123456789>

PC Version Messages
These messages are carried over from the PC version of the game. A good few of them were unused there too.
 * SHOW MAP: OFF
 * ACTIVATED
 * LOCKED
 * GIVING EVERYTHING!
 * ALL DOORS UNLOCKED
 * SWITCH OPERATED ONLY!
 * GOD MODE: ON
 * GOD MODE: OFF
 * YOU'RE TOO GOOD TO BE CHEATING!
 * CHEAT CODE: UNRECOGNIZED
 * HOLODUKE NOT FOUND YET!
 * JETPACK NOT FOUND YET!
 * ALL LOCKS TOGGLED
 * YOU'RE BURNING!
 * SHOW MAP: ON
 * !!! INCORRECT VERSION !!!
 * GOT ALL INVENTORY
 * GOT ALL KEYS
 * MAP HAS A DIFFERENT NUMBER OF PLAYERS

Unused Music
A number of songs on the disc aren't used. Song names taken from the composer's website...
 * Metallic Horrific 1 - An unused original track. Why it didn't make the cut is unknown.
 * Pob - An arrangement of a track from Atomic Edition. Used, strangely enough, in the "Blank" map.

Extra Music
As mentioned in the manual, the game disc contains three redbook audio tracks that are played while you're in the game. Surprisingly, those three tracks are also stored as WAV files on the disc, and were probably used to pad the game data.
 * 28DISTOR.WAV
 * 30CHAING.WAV
 * 38CHEMIC.WAV

Unused Sounds
There are new sounds for three new enemies (Pig-in-a-Dress, Underwater Drone and Zombie Pig Cop) spotting the player. Similar to the Sentry Drone in the PC version, there is also an unused dying sound for the Underwater Drone.

Unused Level
E1L9 is called "Blank" and consists of a small C-shaped room covered in the default texture and nothing else. Curiously, an unused track (Pob) is assigned to this map.

The map appears to be a placeholder, as the artwork and sounds used in the menus or screens are packed with the E1L9.PMP file. As a result sprites appear to be glitchy in this level, due to gameplay related artwork not being included in the PMP file.

Hidden Sprite
A room in E4L3 (Gates Motel) contains a typewriter that only appears in this room. However, it's impossible to see this object without the noclip cheat, as you can only enter the room by exploding the door - the typewriter is caught in the blast and destroyed.

Unused Skill Setting
While the hardest skill level (Damn I'm Good) was removed from this version of the game, several levels - including from the PSX-exclusive Plug and Pray episode - contains enemies that are flagged to only be present on that skill.

Single-Player and Multiplayer Content
Unlike the PC version, the PSX version only allows 10 specific maps to be played in multiplayer, by way of a hidden 5th episode (Butt Kicking Zone) that contains slighly modified versions of maps from the main episodes along with a single exclusive map (Quirk of Fate).

Despite that, many maps contain sprites and actors flagged to only appear in single-player, multiplayer or, strangely, co-op (which doesn't exist in this port). It should also be noted that most levels have keycard switches on both sides of locked doors, which serves only for multiplayer.

This makes sense for maps that were ported over from the PC version, but this also extends to the PSX-exclusive levels:
 * E4L1 (Nightmare Zone): Co-operative and Dukematch spawn points, multiplayer-only items and switches.
 * E4L2 (Trackside Tragedy): Dukematch spawn points, multiplayer-only items.
 * E4L3 (Gates Motel): Co-operative and Dukematch spawn points (swapped).
 * E4L4 (Duke Royale): Co-operative and Dukematch spawn points, multiplayer-only items and switches.
 * E4L5 (Alien Rendezvous): This map has no multiplayer content, also the geometry would prevent the level from being completed (or even played) outside of single-player.
 * E4L6 (Ministry of Fear): Co-operative and Dukematch spawn points (swapped), multiplayer-only items
 * E5L1 (Quirk of Fate): Enemies (this is a Dukematch-only level, so enemies cannot be seen without cheats).