In case anyone is curious about who made your favourite (and least favourite) rooms... well, you've probably noticed that the hold credits each level to its main architect. But that's not the whole story. Through the long development process, a lot of people contributed rooms to each other's levels, so I've kept a list in case you wanted to know about any specific room.
by X (ed. Y)"
when the version we went with was substantially edited by another architect; of course there were many small edits along the way and there was no point in attempting to track all of these.
The list will reveal the names of levels, so only look if you don't mind seeing these. Secret levels are listed in a spoiler within the spoiler.
×Silent Woods (12th Archivist)
1N1E by bomber50
Ruined Entryway (Moo)
1N1E by Nuntar
2N2E, 1N3E by bomber50
3E by Dragon Fogel
Winding Passage (bomber50)
1N, 2N by Nuntar
2N2E by Nuntar and Dragon Fogel
2N8E by 12th Archivist
The Fork of Infinity (Pinnacle)
1S1W by Nuntar
Hall of Arrows (Pinnacle/blorx1)
1N1W, 1S1W, 1S1E by blorx1
1N1E by 12th Archivist (ed. Nuntar)
Other rooms by Pinnacle
Upper Stoneworks (12th Archivist)
2E by Nuntar
Breeding Grounds (Nuntar)
3E, 1S3E by PigmyWubba
Interlude: A Geothermal Jaunt (12th Archivist/blorx1)
West and East rooms by blorx1
Central rooms and 4N2W by 12th Archivist
Infested Furnace (Pinnacle)
1S1E by mauvebutterfly
Magma Mausoleum (bomber50)
2S1E, 2S3E by Jacob
Riptide Currents (12th Archivist/Kieran Millar)
3N by 12th Archivist (ed. Nuntar)
2N, 1N1E, 3S by Kieran Millar
1S1E by Nuntar
2E, 1S2E by averagemoe
Other rooms by 12th Archivist
Blasted Ruins (hyperme/Pinnacle)
3N, 3N1E, 3N2E, 2N1E by Pinnacle
2S1E, 2N2E by PigmyWubba
Other rooms by hyperme
Haunted Courtyard (Nuntar)
1N2E, 1S2E by Dragon Fogel
Ashen Cavern (blorx1)
3N1E by Nuntar
Desolate Warehouse (bomber50)
1S1W by Dragon Fogel
Potion Distillery (Pinnacle)
1W by blorx1 (ed. Nuntar)
1S, 2S by Dragon Fogel
Parched Plaza (12th Archivist)
1N3E by Kieran Millar
Beyond the Veil (Nuntar/Crimson Moon/Jeff_Ray/NoahT)
Entrance, 2N1E, 1E, 1N3E, 1N4E by Nuntar
1N, 1N1E by Crimson Moon
1N2E by Crimson Moon (ed. NoahT)
2E, 1S, 1S1E, 1S2E by Jeff_Ray
2N, 1N1W, 1S1W, 2S, 2S1E by NoahT
Corroded Mines (hyperme)
3S1E by Pinnacle
Blue Stuff (Jutt)
1S by Nuntar
4N2W, 4N2E by averagemoe
Vipers' Nest (Kieran Millar)
2S1E by blorx1
Smouldering Fissure (Pinnacle/mauvebutterfly)
Entrance, 1N, 1N1E, 3N1W, 4N, 6N by mauvebutterfly
1N1W by Nuntar (ed. Dragon Fogel)
Other rooms by Pinnacle
Subterranean Garrison (Kieran Millar)
3N1E by hyperme
5N by blorx1
Botanical Gardens (blorx1)
2S1W by Kieran Millar
2N2W by Nuntar
Interlude: Oznik's Revenge (Larry Murk/Nuntar)
Entrance, 1N1W, 2N2W, 4N1W by Nuntar
1N, 2N1W by Kieran Millar
Other rooms by Larry Murk
Red Rock Hermitage (Nuntar)
3N2W by Pinnacle
Pulsating Crater (PigmyWubba)
1E by Nuntar
Carnivorous Causeway (hyperme)
1S1E, 2S by Dragon Fogel
2S1W by Nuntar
Viscous Incubator (Nuntar)
2N, 2N1W, 3N2E by Pinnacle
2N2E by 12th Archivist
6N2E by PigmyWubba
Nival Terrarium (Nuntar/PigmyWubba)
2N1W, 3N1W, 4N2W, 4N1W, 4N1E, 4N2E, 5N1E by PigmyWubba
Other rooms by Nuntar
Interlude: Winged Words (Larry Murk)
5N1E by Nuntar
Unreal City (Nuntar)
3N1E by uncopy2002
Searing Depths (Nuntar/Larry Murk)
1S1E, 2S1E, 3S1E, 4S1E by Larry Murk
Other rooms by Nuntar
Lower Stoneworks (Insoluble)
3N by Dragon Fogel
Bionic Enhancement Sector (PigmyWubba)
1N1E by hyperme
2S2E by Spleen
2S1W by PigmyWubba (ed. Nuntar)
5S1W by navithmastero (ed. Dragon Fogel)
Cerebral Testing Facility (blorx1)
1E by Nuntar
1N1E by PigmyWubba
2N2E by 12th Archivist
Green Stuff (PigmyWubba)
3N2W by Nuntar
2N1W by Dragon Fogel
Depleted Quarry (Jeff_Ray)
1S1E by Dragon Fogel
5E by PigmyWubba
Chrome Foundry (Crimson Moon)
1N2W by Nuntar
2N2W by Crimson Moon (ed. Lucky Luc)
1N1W, 2N1W, 3N2W, 3N1W, 3N, 3N1E by Crimson Moon (ed. Dragon Fogel)
3N2E by PigmyWubba
1N3W, 2N1E by Dying Flutchman
2N by Dragon Fogel
Wrecking Yard (Dragon Fogel/Spleen)
2N1W by Crimson Moon (ed. Dragon Fogel)
8N1E by Crimson Moon (ed. Lucky Luc)
1N1E, 2N1E, 4N1E, 4N2E by Spleen
4N by Spleen (ed. Dragon Fogel)
Outer Sanctum (hyperme)
6N by Insoluble
Interlude: Subversive Engineering (hyperme)
4N2E by Dragon Fogel
Coordinated Assault (blorx1)
1N1E, 2N1E by blorx1 (ed. Nuntar)
2N2E, 1N3E by Nuntar
3E by surrealcanine (ed. Nuntar and Dragon Fogel)
6E by Nuntar (ed. Dragon Fogel)
1S6E by Nuntar (ed. blorx1)
1S7E by Dragon Fogel
Cold Stuff (hyperme)
1S, 1N5E, 1N6E by Dragon Fogel
7E by Nuntar
Thermal Substation (Dragon Fogel/mxvladi)
Entrance, 1N by Nuntar
1N1E, 1N2E, 2E, 3E, 1S1E, 1S2E, 1S3E, 2S, 3S, 2S3E by Dragon Fogel
2S1E by NoahT
Other rooms by mxvladi
Murderous Manufactory (Dragon Fogel)
2N1E by PigmyWubba
Synergic Motor (mauvebutterfly)
1N1E by Nuntar
3W by Jeff_Ray
1S1W by Pinnacle
3S by blorx1
Primary Control Tower: First Floor (blorx1)
2N1E by Dragon Fogel
Interlude: Emergency Protocol (Kieran Millar)
1W, 4W by Larry Murk
Primary Control Tower: Third Floor (Various Architects)
1S, 2S, 1S1W, 2S1W by Jutt
1N, 2N, 1N1W, 2N1W by hyperme
1S2W, 1S3W, 2S2W, 2S3W by Kieran Millar
1N2W, 1N3W, 2N2W, 2N3W by Pinnacle
1N4W, 1N5W, 2N4W, 2N5W by mauvebutterfly
1S4W, 2S5W by Nuntar
1S5W, 2S4W by NoahT
Primary Control Tower: Fourth Floor (Lucky Luc/Nuntar)
1E, 2E, 4E, 1S3E by Nuntar
1N4E, 5E, 1S4E by Lucky Luc (ed. Nuntar)
Other rooms by Lucky Luc
Secret levels and Chapter 8:
Click here to view the secret text
×Sunken Atrium (mauvebutterfly)
1S1W, 2S, 1S1E by PigmyWubba
Deep Hall of Arrows (Pinnacle/blorx1)
1N1E, 1S1W, 1S1E by blorx1
1N1W by 12th Archivist (ed. Nuntar)
Other rooms by Pinnacle
Scorching Sands (Nuntar)
1N3E by Pinnacle
Satoko's Swimming Pool (surrealcanine/Nuntar)
Entrance, 1W, 2W, 1S3W by Nuntar
1S2W, 1N2W by surrealcanine (ed. Nuntar)
Other rooms by surrealcanine
Unnatural History Museum (Xindaris)
1N1W, 1N by Dragon Fogel
1N1E by Dragon Fogel (ed. Nuntar)
Alchemical Annex (blorx1)
1S, 1E by Pinnacle
Turbulent Grotto (PigmyWubba/blorx1)
1N, 1W, 2W, 1E, 1S1E by blorx1
Other rooms by PigmyWubba
Evil Stuff (Dragon Fogel)
2N2W, 1N2W by mauvebutterfly
2N, 2N1E, 3E, 1S2E by uncopy2002
1S1E by Pinnacle
2S2W by blorx1
Interlude: The Slayerly Arts (hyperme)
3S2E by Dragon Fogel
Royal Waterways (Lucky Luc)
2S3E by Dragon Fogel
The Floating Road (Xindaris)
2N2W by Pearls
Oh No! More Lemmings (Red-XIII/Pinnacle)
1N1E, 2S1W, 2S, 2S1E by Pinnacle
Other rooms by Red-XIII
Unstable Core (Various Architects)
1N2E, 2W, 1W, 3E, 1S1W, 2S3E by Xindaris
1N1W, 1N1E, 1N3E, 1S, 1S1E, 1S2E, 1S4E by Red-XIII
3W, 1E, 4E, 5E, 1S3E, 2S2E by Dragon Fogel
1N2W, 2S4E by hyperme
1S2W, 2S1W by mauvebutterfly
2E by Nuntar
Celestial Summit (hyperme/Pinnacle)
Entrance, 1N, 2N, 3N by Pinnacle
5N1E by Dragon Fogel
5N, 5N1W, 7N by Red-XIII
Other rooms by hyperme