No ammo, no reloading, no stupid hands at the end of the gun that look stuffty and the default gun sound and projectiles.
Simple low-poly blocky guns that aren't modeled after guns from Modern Warefare or Halo. They go by power to speed. Small weapons get an akimbo version.
Power to Speed:
Rocket Launcher
Sniper Rifle (bullets are fast, do great amounts of damage) already made
Shotgun (large amounts of damage, really slow) already made
Magnum Rifle (fair damage, a little slow to shoot)
Revolver (fair damage and normal)
Heavy Gun (more damage than the gun, but fires slower)
Gun
Smg (not much accuracy, range or damage but automatic)