This is a... well, it's not really anything in particular, there's elements of temple, wood house, rock canyon, water, but really it's just a monster arena, a map designed with gameplay first. It is also very hard, although skill 2 is quite manageable.
It uses afrits (those flying barons from Scythe 2) instead of cyberdemons; there is only one of the latter. This is probably because the level has an open design and uses height differences instead of walls to guide the player where it wants him to go next, but wants to allow monsters to freely traverse the arena. There are more flying monsters than on a usual map, a large group of cacodemons early on, and lost souls (which are upgraded to an absolute horde of pain elementals on skill 4 - I have no idea how anyone is meant to deal with this, given the map is explicitly designed for Boom compatibility which has no lost soul limit).
It is quite top-heavy (on skill 2) - once you clear out the imp trap you can retreat to the wood house there (the defensible location as I referred to it mentally) and fight things as they float in.
This map requires CC4-tex, which doesn't seem to have a separate download but I believe is distributed inside the Community Chest 4 zip.
This thing on the other hand has CC4-tex statically linked, so it's a huge file and a waste of space if you already have CC4-tex. There's really no good solution...
Eleven maps of the "advanced Boom" variety. I'm not a fan of maps with too much Boom stuff in them, especially the more fragile exotic features. (Impure Offering, while requiring Boom complevel, still played mostly like a Doom map.)
This also has a gimmick of two monsters per map. I didn't realise this at first but managed to play six or so levels before spotting the pattern. Not unsurprisingly, archviles often feature as one of the choices.
- Unit 731 (troopers/archviles) - a laboratory studying captured aliens, that suffers a catastrophe. Requires punching archviles. Final trap is rather vicious (fight three archviles with only your fists!) but doable by learning where the monsters will appear and hiding in a corner.
- From The Sky (chaingunners/archviles) - rooftop assault. Both you and monsters often drop down from ceilings. You start being thrown from a helicopter that looks like a saucepan. I couldn't finish this map due to a very strange bug which is worthy of further analysis (see below)
- Shooting with Imps (sergeants/imps) - I think there's a base under here somewhere, but mainly it just exists to use every different colour variation of each texture in one go. Nostalgia for CC4 testing.
- Orange Night (imps/mancubi) - large city-style map with great height variation to start and ends with a big fight in a car park. CC4-tex lends itself towards garishly-coloured maps. Good fun though, gives you shells and later rockets and throws monsters at you. Seems incomplete, there is a whole section of well-crafted architecture beyond the unmarked exit line.
- Eternity's Hatred (pain elementals/archviles) A hellish temple featuring mostly archviles and a ghost pain elemental (you need to play it on the correct compatibility level). Needs archvile jumps for secrets.
- Pool of the Spiders (cacodemons/barons) - a trek through caves and canyons. Spacious and plentiful in rockets/plasma makes for fun gameplay. A pity the monster teleporter is badly designed and takes forever to deploy fully. No spiders to be seen.
- Casing Lake (sergeants/arachnotrons) - typical ArmouredBlood "Give Me All The Demons" map with much copypaste, massive amounts of ammunition, and numbers of monsters. Prepare to shoot from cover at hordes of teleporting sergeants.
- The Demon Rush (chaingunners/demons) - you are chased through a maze by about 500 demons. A few chaingunners appear to hinder you at times. This is not about killing monsters, you have to keep moving through various obstacles before you are surrounded. I liked this map, it's clever and well set-up. At the end, if you feel like waiting you can make all the monsters run into a giant crusher.
- Leviathan (barons/archviles) - two or three (depending on skill level) symmetrically (over)detailed monster arenas. Theme of being surrounded by barons (outside a fence, so you can't herd them into a crowd) then adding archviles one at a time, and removing pillars you can use for cover.
- Onyx (chaingunners/revenants) - Ribbiks map (Stardate, SWTW). Starts with a forced pillar jumping sequence. Give me a break. This put me off the rest of the map, which is obnoxiously hard, even on HNTR. Not his best effort.
- The Stone Spinneret (arachnotrons/spiderdemons) - similar idea to map 9 (same author); highly detailed monster arenas, using the same teleporter skill flags trick. Framerate-harming amounts of masked 2-sided middle textures. I found skill 2 pretty fun. On skill 4 in the second arena there seem to be some arachnotrons that don't wake up, preventing 100% kills.
Analysis of sudden death bug in From The Sky (MAYhem13 map02)
Bug: After approximately 7 minutes of playing, you die. Unceremoniously, and without warning, the screen goes red and you fall to the floor. Therefore you have only 7 minutes to finish the whole map. This happens regardless of skill level or any other relevant setting.
Explanation: There is a group of control sectors containing conveyor floors and voodoo dolls, for Boom linedef scripting purposes. Some of these voodoo dolls move forward (north in this case) constantly, and are continually teleported back to their start position, in a loop. In this map, silent line-to-line teleporters are used to do this. These position the teleported mobj such that its distance along the teleport linedef is preserved at the destination.
Now, as anyone who has tried to record a demo featuring a glide through a 32-width gap knows, Doom's angle tables are not exact. In particular, an object moving north suffers a very slight motion east. Using a silent line-to-line teleporter preserves this slight horizontal aberration, which slowly accumulates.
After 7 minutes, one particular voodoo doll (thing #85) has drifted sufficiently eastwards to impinge upon a second voodoo doll (thing #192) in the control sector area. Telefragging occurs. You die.