Mikko Sandt has reviewed "Submachine" for his site, MSDN, which gathers Duke reviews for about 20 years. The map has scored 95/100 and you can read the review under this link: Msdn.duke4.net
Also posting some short videos presenting a bunch of effects and tricks done basing on the same "slide door" effect from the original game.
A large tentacle in one of the caves that keeps waving around and making slimy noises:
"Klingon" door with a teeth in the middle, based on a design seen on Klingon vessels from "Star Trek: The Next Generation":
A split-door that cast light upon opening that is properly synchronised with the door movement - and also this is compatible with regular lightswitch in the room:
A pushable cupboard with some play on inertia of the objects located on the cupboard (a cup and a magazine/DVD), also notice how the shadow is changing depending on the position of the cupboard:
Play the map if you still haven't!