When you pick up the ammo box, it's 50%-50% chance to get either one of the weapons, so just keep on shooting and picking up, when you'll have time! :D
New weapons and a menu system are in the making! ;)
My bad then just got bad rng :p i tested again and got it, really cool too, you probably planned it but all it needs right now is some "burn" effect so that players take damage from the fire for a while after being flamed up, curious to see what you'll come up with for the other weapons XD
Well, I'll be honest, I didn't even think about the burning effect, even tho it seems so obvious... XD You have a VIP place in the credits' "Special Thanks" section, now! :D