Very interesting! Here are the differences I could tell:
*The
unused title screen graphic in DN3D's files is shown in the footage! Apparently, the transparent parts in the title would show a burning city.
*Tripwire mines appear to be slightly bugged. It took the player a few seconds for the game to register that the player was touching a mine.
*Level is completely different from anything seen in LD or the final game. It seems to be a bit like something you would see in LD, as most of the level consists of tight corridors. The levels also have lots of dark areas, like LD's space levels do.
*Most of the textures used appear in the final's space levels.
*The Troopers use the design that appears in the preview images released in June 1995. When they are killed by the Plasma Cannon, their sprite jumps back a bit to simulate being shot back by a frickin' powerful plasma ball.
*The green flying robots from Lameduke appear in this build! They seem to work like they did in LD, but their attacks do no damage. At the end of the Indian guy's session, he's in a room with several robots shooting him. In LD, he would've taken significant damage, but he's unharmed after several seconds of fire.
*Pipebombs seem much less powerful than they are in the final game. The Indian guy detonates a pipebomb near himself, but only loses about 60 health. In the final game, he would be dead.
*The explosion sprite that appears when a plasma ball hits something is different from Lameduke.
*The font used for in-game messages is completely different from anything in LD or the final game.
*Windows showing the skybox in space levels can be destroyed. If they are, any enemy in the room will be sucked out while airlock doors seal the breech. It seems to be a bit bugged, as the enemies instead are sucked near a window and are tossed around, like they're in a tornado, instead of actually being ejected.
*Armor is in the game, but it seems to work a bit differently from the final game. From what I can tell, armor completely absorbs most attacks. When the players are being harassed by Troopers, their armor goes down, but not their health. However, this doesn't work for tripwire blasts. The tripwire blasts instantly kills the player from 100 health, but no armor points are deducted.
*The enemy alert message from LD is used and appears to be used every time an enemy detects the player, unlike Lameduke.
*When the first player starts, the message "Loading Quick Game..." appears. My guess is that a quicksave putting the players at the start of a level was made so the producers wouldn't have to muck around with an in-game level select or command-line parameters everytime they needed to start recording.