God damn, that cult death scream is the funniest goddamn thing I've heard in a long while.
Couple of things. Liked the weighty controls, good departure from the usual 2.5D shooter weightless everything without going full Citadel. Acceleration on stopping was a little slippery, though, for that speed.
Art style is actually pretty nice and works, although could use some more assets. You don't need full animations - not for this artstyle - but playing into the physical comedy of these slightly pathetic cultists would do some wonders. I think you've established that you're pretty miserable doing art, but it's pretty endearing. Weapons generally felt pretty good.
Don't be afraid of a little repetition for levels. Demo level seemed like it was in a rush to introduce new elements, themes, enemies and such - generally, oldschool shooters do that on a per-level basis (per chapter, in the case of Duke3D), not 8-times-per-level.
But yeah, had fun from start to end. The secrets in particular were exceptionally fun to find. That jerkoff closet will haunt me for a while, and isn't that the purpose of art?