Most of the time i was dying without understanding what was hitting me.
It looks like all have the same hitbox and damage? so Headshot seems to make the same damage, thats not coool.
The Enemies are stuck often within those Squares, makes it easy to kill and kinda Boring, besides that Turrets the enemies are negetable.
How much you need to damage those Big Robot? It seems not to die.
I think you invested alot into the Level Design, which turned out nice and interesting, the scale is good.
No Game breaking Bugs, everything seems to work, good job.