There are four basic guns: rifle, rocket, pulse, and beam, and each has their own unique firing styles and ammos, and each can be eventually turned into an entirely new gun altogether. For example, the rifle stars out as an assault rifle, but depending on how you upgrade the stock, barrel, ammo, and other things, you can make it into a shotgun, a sniper rifle, or potentially even a submachine gun. The Pulse gun is essentially a continually firing ray gun with a beam that goes quite a distance, but until upgraded, seems to do hardly any damage. The rocket gun is pretty obvious what it is: It’s a rocket launcher. You can upgrade it to shoot more rockets, hold more rockets, and many other things. The pulse gun is something that I really think is cool. It shoots what seem to be small bolts/balls of electricity at your enemies. Unfortunately I have not looked at any of the upgrades for the pulse gun.
Loadout is available on Steam and is free to play.