Yeah... this level would never work as a Deathmatch level. Due to none of the triggers being removed, everything is still in a linear nature if you are in the starting area or you are forced to wait for the starting people to trigger the door to your freedom.
So, basically, only people that know about the secret and triggered it before going down the river could go back. This is a pretty evil example of needing to know the map prior to playing it in Deathmatch. As there are many ways to teleport to the Radioactive Container room and a Rocket Launcher exists nearby, it is pretty easy to camp and kill those that teleport to this room.
Beyond the tacked on Grenade Launcher and Cells, there is little to no difference between this and the normal version. I do get to show off more flaws of the "organic river", such as gapes where no Water exists (due to how Water is managed in Thred, especially if this was done without access to a Texture View, this is no surprise).
I also get to show off something I couldn't do in the Singleplayer game due to it preventing my ability to finish the level. While I stepped off the world into the void beyond, I stayed close enough so that I could return. With no fear of being permanently stuck, I leaped into the void. Due to the broken clipping of being in such a place, it looks quite blurry and chaotic (it is the same as noclipping into the void). You can even see my frame rate counter at various points due to the game being unable to properly render this area. Still, it is a rare experience to see yourself falling repeatedly past the rooms with no real ability to return. I wonder how a deathmatch in such an environment would work!