Played your maps. They were OK, nothing really wowed me, other than the music which was quite good and definitely the highlight of the wad. Here is some criticism which is meant to be constructive and helpful as opposed to antagonistic and off-putting (which is how I always worry I will come across when I write things like this).
I feel like these maps had a lot of potential for interesting gameplay scenarios that just didn't get used very well. Some examples from map 01: the imps+cacos ambush when you grab the megaarmour would be much more fun if you didn't really have that whole outside area to move around in; The fight with the Hell nobles for the red key would be harder if the walls were closer; the revenant horde behind the yellow key door is easily delt with just by stepping outside the door and spamming rockets. The difficulty on UV felt like how it should be on HNTR. I don't want to suggest that the only way to make a map fun is to make it hard, but I feel like a lot of new-ish mappers are afraid to put the player in any really serious danger, or overestimate the danger of certain scenarios (there was no need for any of those invulnerabilities), and as such the gameplay suffers.
I had more fun with Map 02 playing from pistol start, because the at least the first bit of the map requires you to play carefully as opposed to just showering everything with bullets and calling it a day.
Also, considering you said that they are ZDoom maps, I don't see any ZDoom features here. I think you could benefit from some: there are far too many encounters where the player can just run away easily, which could be easily stopped with ZDoom by requiring killing certain monsters to open doors or whatever. Or, make it Boom-compatible and you will probably get more response, at least here on Doomworld.
The visuals are fairly plain, there are some good moments and the caves look nice with the cracks in the floor but there's too many single-textured hallways or plain square designs. I did like the look of the monster teleport pads inlayed in the ground, and the last rooms of the second map were OK, could've been much improved with some dramatic lighting.
Again the music is really good and it's always nice to hear new compositions for maps.
Anyhow like I said before this is meant to be helpful, if you found it hurtful or you just disagree feel free to ignore me entirely :P I did have some fun with these maps, I just feel they didn't live up to their potential.
It wasn't hurtful at all. At least you gave legitimate feedback instead of just saying "WTF DEEZ MAPS SUX" (don't worry, I didn't misinterpret it like that).
As for more specific points, I know I didn't use too many ZDoom features, but I usually choose to map for it because it's basically been my port of choice since 2009. And even personally, I do feel that the full potential of my mapping was left unused. I did use more of it this time, though; this one is like the tenth wad or so that I've released publicly, and as opposed to my previous works, the map layouts in this wad are less agonizingly linear. Just take a look at Bleeding Skies or Stana Prkle by me if you don't believe me. :P
Lastly, I do agree with you that the music is definitely the strong point of the wad.
I am mad. I am Finnish. I am a gamer. But I don't know where the number 38 came from.