Wow this is a cool looking game :O, and well done getting the loop running. You kicked ass as a single dev working on this. I had few issues, but still managed to have a lot of fun with this, so please keep working on this. I think more enemy variety (they all look unique but don't do much differently), stopping the mech from covering the crosshairs so you can see where you're shooting, and giving the primary weapon some love would be amazing. Perhaps a simple upgrade system that forces the player to explore would be nice.
Also nice job with the sfx and music, you really made something dope ^_^