Let's start with basic looks. It looks like a hunk of hardware from alien mixed with hardware from halo. Basic Appeal is there, it has battery, ready and os (overload situation?) indicators for simple info. Point for usability. I can see sciency'ish sights applied but they also un-mountable. Another point for thinking through. Main release chamber has piece of gauss accelerator sticking out, no doubt for quick replacing of outcoming plasma/coil last accelerator cascade (one which overloaded the most == gets used up more oftenly). Overwall it is a definitely nice work, which even without some basic switches (firemode switch to example) which can do well in many AAA projects.
This is a very interesting-looking weapon, yet nothing like ergonomical or actually usable. Grip it too small for a human hand - and the angled stock is clearly unusable - anyone who would dare to take this weapon into combat would suffer from it slipping down from shoulder and messing with aim. And the other part is that foregrip is too close to the main grip, which adds even more discomfort. This weapon looks bulky and menacing from a first glance - yet second one reveals its flaws and makes this concept rather funny. Overall - nice work with textures, nice looking metal, interesting idea - yet very bed work with ergonomics.
I promised I wouldn't write another critique, but this thing is just ridiculous. In a good way, though. I don't know what the hell I'd do with it, but that makes me want to figure out what I'm supposed to do with it. I looks heavy and kinda clunky, but huge and powerful. Like home destruction powerful.
The fonts used for the fire select etc look too cute, this is the same with a lot of your pieces, also I think the bar codes on other weapons make it look like a toy and less believable - You should really try and improve on that because every other area of your work is near perfect.