UAC constructed a bolt-hole on the dark side of the moon which was terraformed for the purpose. It was known as the Waterwheel because of its shape. When you completed the cleanup at Deimos you were warped to the Waterwheel because the infestation had spread even there. You find yourself transported to the centre of the Waterwheel and need to find your way to the exit warp-point cleaning up as you go.
Sadly, the hell spawn has already carved holes into the roof and the upper levels have been flooded. Fortunately, door blocks have prevented the flooding from spreading to the control rooms that make up the wheel(s) and the lower levels where the bugs from hell have constructed their dead-rooms.
Download the REAL file here (rd1.zip is NOT correct) https://www.doomworld.com/idgames/levels/doom2/megawads/d64d2
Shocked to see so many negative reviews. I had an absolute blast with this one, and I'm not sure what Nems was talking about with the Boom stuff as this runs in Doom2.exe with no trouble. In fact, there is a TON of impressive vanilla stuff going on here. I guess it was so well done that it tricked him.
This deserves a high score. It's a lot of fun.
It definitely makes Doom look darker, but also slightly changes colors (it reminds me PSX Doom). I prefer original Doom colors and miss how it looked on CRT (almost same colors as with modern monitors, but less brightness and maybe more contrast).
I honestly can't believe that this whole megawad is 100% vanilla compatible and its only the first of THREE episodic megawads! Esselfortium and her team of creative energetic mappers has done an amazing job from the unique texture set, the music, the maps & even the tweaked color palette that fits the mood of the whole thing.
100% highly recommended! 5/5