A FPS with a single (but important) merit: it's free
But do not misunderstand me: this game fails. It's highly repetitive, lots of maps are simply too big to be funny, and it's always - always- full of cheaters. You can't enjoy even the best game, when an invisible invincible sniper with a rifle that shoots superatomic bullets flies over your head.
So I'll give it a 6, but just because it's free. Yes, maybe you should download it, register and play it. But probably in a week or two you'll abandon it. Well, if you're not an hacker... if you are, congratulations! You actually found paradise.