Great game, I love the art and the sound design and the general "gamefeel" of moving around in the giant mech, you definitely got it down.
Performance (mainly stutters) was one of the main downsides but I think that can easily be fixed.
Level design at least in the first few levels looked (but not played) very undercooked, but honestly you shouldn't worry about that until close to release or unless you want some really nice screenshots for promotional material.
About the weapon switching and the shotgun, the shotgun either fires way too slow or doesn't do enough damage(which sucks because I love shotguns), at least not enough to be used instead of the gatling gun. when I would use it, it wasn't very rewarding as when I wanted to switch off of it the switching felt too slow.
A way to fix the feel of weapon switching if you want to keep the weapon switching slow (it's a giant mech hauling around giant weapons so I don't blame you if you do) would be to add some feedback, probably with a sound file that plays when switching or some bouncy first-person animations for the switching.
One thing with the lock-on launcher, It felt really inconsistent to use. I'm not sure if it was modeled after the SPIKE LR2 where it shoots up into the air before coming back down, so in my case it kept smashing into the ceiling. But sometimes it would just fly straight towards the enemy and insta-kill them (which felt really rewarding.) Not sure if bug or just quirk of using the weapon so it wouldn't be too OP compared to the other secondaries (which it almost already feels like, because I wouldn't use any of the other secondary weapons.)
Overall, great art, great gameplay, great sound design, performance can be fixed, map design can be worked on later when you feel comfortable with the rest of the game.
All in all, I think this game is GMI.
(Only other game you have to compete with is Psycho Patrol R, but his art style isn't for everyone and from the looks of it, the actual mech gameplay doesn't look nearly as fun as what (A)woken currently has.