Cute little wargame with lots of potential. Might I recommend for weapons you colour code them or symbol them so it's clearer if a certain weapon is one handed or two? (e.g. blue/circle for one handed, red/square for two handed). I say this due to the issue of weapons like the antimaterial rifle or phaseblade for example not being clear if it is a two handed or one handed weapon weapon. Also it isn't clear as to what the rules of one handed vs two handed weapons are, as it is simply a stat at the moment and the book doesn't explain what these rules do.
You could also expand the vehicle roster as I have seen some of your art and other forms of vehicles are present like aircraft. Perhaps you could introduce a similar system to the honours system where players can exchange scrap for upgrading vehicles? Having a shark drive a one person submarine with tank treads seems very in character and funny, and justifies how strong the missile launcher is currently without nerfing it.