Combat arms is fun but it has the worst community I've ever seen in a game. Any one with a KD over 1 will usually get kicked around 75% of the time for "Chamming" which is the stupidest name I've ever heard for wallhacking. I am not a wall hacker combat armers footsteps are loud. And firing a gun randomly does not make you any quieter. (dont try to explain that to them it gets you kicked faster)
I stopped playing it because dystopia was also free and much much better. And had no pay for content junk. Gotta love source mods and decent communities.
The Game: Combat Arms is a fairly Generic shooter that requires constant grinding to get ingame money to temporarily buy guns, helmets, armors, and camo. Once you level up to around midway this becomes a real chore because you dont get level up money that much any more. For real world money you can buy more temporary things like smily face masks, new character models, fancy guns, ect. It also lets you buy "eliet" status so you can go into any server and kick people when you feel like it. This turns out horribly so I avoided any server with an eliet playing in it. Theirs a handly little symbol to warn you that theres an eliet ingame beside the server.
It has the basic game modes like ctf (only the worst maps are available for ctf), team deathmatch and bomb plant. They also came out with a coop game mode where you fight off swarms of horrid ai for a minor amount of ingame money. Enemies will actually spawn in your face with an already primed grenade every once in a while because you have to kill every enemy in the spawn que or they'll just spawn in your face. Think zerg max pop cap in zerglings for the ai count. I haven't played the zombie mode.