Alright, I gave it quite a long round in vanilla Doom 2, and while I enjoyed the heck out of it(and i'll explain why), I think it's far from being completed, in terms of content.
Let's start with the good stuff:
HOLY SHIT THE SOUND DECISIONS IS JUST WONDERFUL! It really makes you feel like you're inside a twin-stick shooter in first-person view, and very loyal to the aesthetic of Smash TV.
Monsters might look completely original at first, but I did realize their inspired behavior from other enemies in Total Carnage. It's a nice touch only if you played that game.
I also found a few easter eggs which made me grin.
The only thing which i fit between the pros and cons is the difficulty concept. Yes, the whole thing with removing the life system is essential for SHMUPs, and that's why this mod would be impossible to play with in slaughter maps like latter maps of Sunlust or even Slaughterfest 2012. HOWEVER, it's great for limited-mapping projects such as 50 Monsters and similar.
Now, about the issues i have with it:
Some character models lack polish in their design. I know that it's supposed to be a sketchy artstyle, but it looks a bit out of place in doom maps(I also give that sort of criticism for any mod which uses this artstyle)
Now personally, i think there should be more gameplay gimmicks, because for the whole playthrough, i haven't got a single occurrence where the traditional Bomb power was effective(i did check your notes). I might be missing something, but the whole purpose of the traditional Bomb power is to destroy everything(excluding bosses) on screen.
I did notice the lack of taunts for this mod. I love both characters and i'd love to hear some one-liners from them. If it's about limitation from the original games, how about recruiting someone to voice them?
And lastly, while it's not too much of an issue, i'd love to see more references from other SHMUPs, or even fan-made SHMUPs like Touhou(won't mind it for only a easter egg).
Overall? it has great potential, and i love the concept to death, but there's still more stuff to do before it'll feel complete.
Also in general, if you need more people for suggestions and ideas for the mod, you can ask me anything on discord
(also because i want more SHMUP buddies
)