My feedback for Inverter Gun:
What the game does well:
Great incorporation of the theme. Enemies get sucked in whole and pushed out as ammo. Straight to the point.
The art stays true to the rules of your tilemap. That is, every object is a 1x1 tile.
Shooting feels good, and is rapid without any noticeable delay
What the game doesn't do well:
The main mechanic that ties the gameplay to the theme, the inverter action, needs polish. Because of how fast the character moves I found myself trying to get closer to suck in an enemy and getting hit instead.
The range doesn't seem that far and only covers whats directly in front of me and nothing in the diagonal area.
Each enemy has a different behavior when they're whole, but when you suck them in, their ammo all do roughly the same thing with nothing separating them apart (aside from the green crawler enemy that shoots 3).
Areas of Opportunity:
The levels are long mazes, and each room feels like the last. But with that much ground to cover you can turn each one into a dungeon. Perhaps there is an item in one room that the player needs for another?
The enemies don't need revising so much as their ammo form. I think you can get creative with things like the ammo's speed, angle, power, etc.
I hope this feedback helps!