I discovered this game from the comment you left, it's really good, I really like the level design, I would totally think those were real doom levels! The secrets are cool, Koko Caine says hi!
The only "problem" that I encountered is that in the second level, in the garden area I fell down to the death river and it took a while to die, maybe you could make that an instadeath or maybe even better, have a way out of the river to the starting area of the garden.
I think that's the only thing I would change, the Korone voice clips are top and the weapons are very funny, I'll add this to my faves and check for new updates once in a while!
I hope you keep making games! Cheers!