Hey man thanks for taking the time to play it and give detailed feedback!
I actually do have the PNG files for hit animations but the code for having the rotating sprites and action animations kept conflicting with each other (hence the reason for no shoot animation being visible, though it exists for one frame). When I get time this weekend I intend to try and fix that.
As for the Duke Nukem/Strife comparison, the big box level design came about because I wanted to submit before Dorian hit. Vents, elevators and stairs got left on the cutting room floor, along with the rocket launcher and melee attack. The stealth mode was also designed to mimic the half-baked stealth of Strife, and a dialogue tree system got cut out.
I do have atleast 3 other "Episodes" planned out (and some enemies even modeled and animated) so I want to get those out, if only to keep my coding skills sharp while I work a devops job. So keep an eye out and you might be happily surprised :)