Looks promising! The guns seem to have a nice feel/ handling to them again like in your old shooter prototypes but the weapons itself are a tad too pixelated for my taste.
Overall there are a few styles clashing with another. The drawn highly pixelated 2D guns (I like the perspective on the guns though), the 3d environment (which is fine IMO, esp. those stonewall texture approach), the static shadow maps and the soft shader flashlight shadowing.

Things you could try:
- Have a look at the RTS "8 bit armies" and their models. You could use that approach for guns (but then you'd have to design enemies in that way too, probably more time consuming).
- Have the flashlight shader put out pixelated shadows, like on an 8 step gradient (that is use the current shadow value and transform it into that).
- Disable static shadow maps (thus flat shadowing only), maybe even all dynamic shader based but pixelated lighting could work out fine and cool.

What are you planning regarding content creation? Fixed levels like Doom 1 or randomly/ procedurally generated levels maybe (with optional loot/ grinding/ exp)?