In Gun Game mode, you begin with a handgun. With each kill you get, you move up through various tiers of weapons. When you get a kill with the final weapon, you will win the game. A melee kill, however, will not advance your weapon tier, but puts the killed player’s tier down to the previous tier.
The weapon tiers are as follows:
Due to the way the weapon tiers progress, you will often be up against opponents with superior weapons. Therefore, remain in cover whenever possible and make sure you know the strengths and weaknesses of your gun.
Listen for opponents that might sneak up on you from behind, especially if you are playing on a small map. Be aware of your surroundings at all times, and keep your eyes on the mini map, as well.
If you have a slow weapon, stay behind cover and try to use contextual lean to get in a shot before your opponent can hit you.