Looks dope. I am just wondering why you try to make Metal Slug style tanks/buildings (nobody does that on itch.io, so you got no competition, aka great for you) but not make in the same way (drop the shading via dithering). I would buy all your assets in a heart beat if you would do it the "SNK" way (looking for art like that).
https://6th-divisions-den.com/ms_tutorial.html