This e-mail is Phil Hammond's.

I think, those who like unusual, strange and original maps might enjoy these levels. Although, the underlying ideas could be realized in much better way...
Screenshot of S1L1 is shown on the screen. This is a big canyon-like... em, building... or something like that. And your path lies from the upper floors to the lower. It sounds interesting, but the gameplay is awful, and the design very cubish (well, as in the rest of maps).
S1L2 is a cross-like room with lava and acid pools. You should activate bridges and collect keys to proceed. It could be a good map, but it's very small (and you can cross acid without bridges), its design is too simple, and its gameplay is too rough. Also, there is a stupid non-solid part of wall (the author very likes this trick and uses it in the other maps). Note: if you can't find level exit, dive into acid pool.
S1L3 is the stupidiest one. Dark tiny corridors, a lot of enemies, lack of ammo, a small secret button with the same texture as on ceiling, and frustrating half-solid platform over pool...
S1L4 is probably the best from gameplay side. It's a real puzzle. But I really hate filckering light in one of the rooms (and on the next map this effect is present again).
S1L5 — very simple in any sense, and too short. It is a couple of rooms connected only by unusual looking teleports.
S1L6 — the last and the funniest one. There are boats with enemies, and boats move around the player place. Maybe, this is the best of these maps, but I don't like very quick death when player is touching acid. Also, there are two shamblers, but you can easily kill them if you'll think for a second.

Interesting thing with these maps: they are very small and cubish, but while I was playing 'em I haven't noticed that, coz I was buisy trying to find out how to move forward (and have spent a lot of time doing that); except S1L2 and S1L5 — they are really too short.
Also, there are no intermissions between maps, you're just spawning on the next level seamlessly, and it seems like you're playing one big map.