I love the sounds you selected! The game runs smoothly, and the art is all in the same universe the lighting and effects are well fitting and good too; not over-done.
Controls wise, I was having a rough time clicking quickly (RSI) with the first mech option, i liked the third option best.
It looked like my bullets disappeared after a set distance, which was really disappointing on being able to snipe guys from far away. Also I think the bullets go to the right a tad of the aim reticle. (not sure)
I had fun with this, the multiple enemy types were good. I wish I had something that was a little better than slowly walking left and right to avoid getting hit. Like timing a shield or better cover or something.