First off, when not in full screen, it takes a bit to get the border up and running with going back to the desktop and enabling and disabling borderless.
Second the mouse sensitive is too low. It takes forever to move where I have to drag my mouse across the table 3 times to move 90 degrees.
I think you should focus on impact. Right now, none of the features have real impact and the enemies feel very tanky. I don't know why it takes 6+ shots to kill a generic enemy. The enemies are all my size too, so I don't feel like I'm a giant robot. More like in an exoskeleton.
I'd highly recommend Armored Core for more fast paced combat with mechas, especially Verdict Day. Slower mecha combat is fine if there is impact, which right now there is none. Overall impact is really important. The slower the game is the more impact matters. Every gunshot/attack pulling it's weight and seeing it in the air with the reaction. Right now it seems most weapons have the same blow up animations or nothing at all. Not sure how possible it is in the engine you are working on, being seeing parts flying would be nice with knockback with bullets.
Basically, if I'm firing a giant robot canon, I want it to feel like I'm using a giant robot canon. If you can nail that, then you will be in a very good place.