Map 12 -- Alpha Tower
A vast map, reminding me somewhat of MM2 map 28 "Corporate Hell" in some ways, covering several large towers, some caverns, marble palaces, brick arenas, and more. Several bits are sparsely populated and the monster count is still 330 on UV (although, a lot of them are released in two set-pieces). The progression is fairly simple: you first make your way to the yellow key which gains access to the central hub whence you can access the red key area and blue key area separately. I believe only one of the keys is needed to get to the exit from there.
Difficulty is hard, especially if playing 100/100 (like I am), if playing from scratch (as I am), if playing without savegames (as I am), and if choosing -- or rather, randomly selecting -- to play the blue key area before the red key area (as I did). I did manage to get through it all in my second attempt, but there were some close calls along the way. The bulk of the opposition is made up of smaller monsters (imps, zombiemen, chaingunners), however droves of the larger monsters make guest appearances throughout, so you're in for a rough time. The ammo balance is fair, but there are ways to play though the map, especially the first half, which could cause you to run out, or almost so, and this adds greatly to the difficulty. There are two set-ups with teleporting monsters; the first, a swarm of imps released in a darkened corridor area was pretty fun, although I was sort of expecting it and ran away to fight all of them from one side, which made things easy. The second, a grab bag of beasts released on a descending platform Š la HR map 31, with a couple of Arch-Viles sent in at the end to try to revive what you spent a lot of time killing, was surprisingly unchallenging, given the vast amounts of plasma ammo given, and that the monsters have a single entry point. I basically stood still and fired continuously at one spot, and not until the very end did I have to seek some cover, when the Barons started teleporting in. Then I just grabbed the BFG and mopped up. No, the challenge was instead surviving early on, when you're ill-equipped and lacking both health and armour, and getting through the marble section, with its gnarly chaingunners and Revenant trap (I was totally expecting some kind of trap there and managed to use the curvature of the corridors to pick the monsters off basically one by one).
There are two secrets: the berserk is useless because I'm not punching through a horde of HKs/Cacos/Revenants when I have the RL, and the computer map is found behind a random piece of unmarked wall. I have no idea why I thought that might be a good place to wallhump but I did find it on my first playthrough by chance. I expect the vast majority of players will not. It all ends with a super cheap Cyber finale, which, had it killed me would have pissed me off to no end after spending almost half an hour playing the map. However, I had the BFG with plenty of ammo and went in 180/180 so I survived. Blowing up the towers to exit the map was, by then, extremely satisfying. This map represents a HUGE step up in difficulty to the first 11 and some players will like its gameplay, some players won't. Overall I thought it was rather fun, minor complaints aside, but I understand why some won't. --4/5
By the way, I noticed that this map has three authors... I wonder what author did what part of the map. Perhaps two people designed the red and blue key areas, respectively, and the third did the rest?