Small Isle - nothing special, but the fact that author bothered to implement actual floating platform instead of normal elevator is neat, the boat adds a bit of doom cute.
Degenerate Fruit - easy follow up, you can get kinda fucked up if your don't prioritize enemies correctly in the first room and be a bit health deprived, but berzerk pack helps with that.
Festering Axe Wound - gotta say right from the start, despite how simple and short it is,
@ArticleWriter's addition is probably my favorite, very clean, compact and I was kinda spooked on my first playthrough when back up squad of imps and shotgunners marched from the hidden spawn at the start, final room poses a bit of challenge due to enemy positioning and limited ammo, absolute

in my eyes.
HRT Labs - another great map, I really liked the room with toxic waste pool and how it was reused later, rocket launcher secret is very Doom 1 like and crate area room has pretty good level of details to it and a decent fight, the only bad thing is how abruptly the level ends, with exit door just looking rather poor, otherwise
@The Bovinian Derivative delivered

.
Uncle Jersh's Day Out - starting street is the best detailed part of any level here, but I kinda didn't like it, there is a lot of very good looking locations, but fights were on a very easy side and in general the whole map was a slow burner, still it's hard not to commend the visuals, I only got 7/12 secrets, honestly have no idea if that's either me being bad or some linedefs not triggering.
Kiwifarms 2041 - neat use of the GZDoom's ability to use non euclidean space, but kinda unremarkable, Cyberdemon at the end can be easily cheeseed from a lot of angles, his position would be a lot more lethal it he was raised a bit higher.
Rat's Den - a very great looking and finely detailed indoor map, being mostly a Tyson map makes it a good break for the pace of the set, can't say anything bad about it, although I have no idea where the last secret is and balcony skybox would bug out like hell on me.
P.S. How could I forget, the

is absolutely brilliant, don't know how to describe the mirth that I experienced when first teleported into it.
Dilation Station 41 - this one is easily the best encounter wise
@Laughing Muttley 
, a significant difficulty spike compared to all previous maps, first two rooms already testing your positioning and ammo usage, after that it keeps with the pressure with "The Pit" style mancubus drop, assault from spectres and chaingunners in the dark and very nasty Plasma Gun room, the only criticism that I have is that secrets in general are kinda weak, and both of those with green armor in them are way too late to be actually useful.
Retard War - good all around, my favorite part is actually the imp cavern at the start, but the stone pit encounter actually forces you to look out for the Mastermind, otherwise he still gets a good sightline to fire at you, the end fight is a nice spectacle and if you literally do what map heavily suggests it will be a cake walk, have no idea how to get into the sofa room so I ended up with only 2/4 secrets, although secrets are absolutely not critical for this one.
YWNBAW - BFG spam, two parts that leave a sour taste are the Baron rooms at the start and full darkness corridor with lost souls, former is not fun to cleanup with shotgun/chaingun, the latter is just painful because you can't see shit and at some point you will fall down without ability to backtrack, this is the only map where I didn't score 100% kills, but all the secrets are fun, although again I only ended up with 8/11, I think that linedefs around burning server didn't trigger.