Great game, you'll love it.
There are tons of weapons available for use, including katanas, swords, sub-machine guns, machine guns, rifles, pistols, revolvers, shotguns, and many more!
You can get even more weapons if you buy 'G-coins' for real world money.
You are able to perform skilled dodges, dashes and other acrobatic stunts.
There are many options, like deathmatch, team deathmatch, quests, and 20 more.
The content is updated regularly, so you won't get bored.
The updates do can take long, this is one of the down-sides of Gunz.
If you are noob, it is pretty hard, because most new players will try to shoot, because they can't fight with a sword so good yet, and most players can dodge every bullet.
Another downside is, that you'll get called a 'sprayer-noob' for using ranged weapons (especially if you use sub-machine guns or machine guns).
Even though it has some downsides, I highly recommend it!