Thanks for recommending this game via your Facebook meme page.
I just finished through all of it and I do see a lot of potential. I'll quickly go over the positives and the things that need improvement without going too much in-depth as I am sure you will be aware of most of the issues yourself.
Normally the shooting mechanics in indie/solo made games are garbage but this game has it nailed down quite well. I was surprised that I did not run into any glitches and the game ran just fine. I also really enjoyed the story narrative you tried to build in the snow, valentine as well as saloon level . I think that that is a nice direction for you to go in and you should implement it in the starting levels as well as any other levels going forward (maybe have an intro where the protagonist gets introduced along with the drone invasion).
Now to the things that require improvement:
Level-design: the themes and ideas are nice, but making giant rooms which are empty until the player triggers a silent spawn queue gets stale very fast. That mechanic should be used sparingly and the rest of the level should have enemies in specific rooms (think of the levels in first 2 games in DOOM).
I understand coding a game is one thing and creating the models is another, but model art style consistency also looks good. I feel like id much rather have enjoyed the shadow gun being low poly and looking in place with the rest of the game rather than it being super high poly to where I feel the uncanny valley effect.
There should be a tutorial level which showcases all controls and teaches the player about weapon and mana spell cooldowns.
The triangle in the right hand is a very nice touch and if you can somehow animate it and make it glow it would look very nice
Also add a proper dialogue box that pops up during the story bits. When I was talking to the bartender if I suddenly moved my mouse slightly away from his model, the game skipped the dialogue entirely and I couldn't read what was being said.
Looking forward for future updates and wishing you the best of luck! You have solid ideas, just polish it a bit and you will have a winner in your hands.