I just played the Trenched demo. The mechs, or "trenches," are upgradable and customizable. In the first mission I unlocked a sniper rifle to use in the next. The basic weapons are two machine gun turrets, one one either side of the trench. They are mapped to the right and left trigger, respectively. It seems that a hard limit on ammo is not a consideration, but reloading is. Reloading takes ti...