Thank you for making this, I enjoyed almost every moment I played it.
But of course there is some job to do. As mentioned above, some maps are too long whereas other ones are short. It would make more sense in more story-driven mod with some NPC interaction on shorter maps and more gameplay on longer ones. Anyway, I like your big maps. It gives me "where the hell am I"-feeling I remember from playing original Doom as a child. And I can see a huge progress between the episodes.
Also, some weapons feel a little useless. I avoided electric analog of rocket launcher and used it only as the last resort. It just makes not enough damage while you still can damage yourself.
Cannot wait your next work. There is a lot of potential for more maps with new skills you learned, new more complicated classes and gameplay features, as well as lore development.