You can access a player's profile by clicking on the link in one of their comments or a forum message, or if their hard to find, appearently you can go to YOUR profile, look at the URL address, and if you know the person's username, you can copy it in the address bar where your username is.
But wouldn't it be easier to be able to search them in a way that is a little more user friendly? Like what do you do when you want to friend somebody? That's what a lot of people want to know. I think ArmorGames should set up some kind of search bar, maybe located in the "Friends" section of your profile, where you can look for the users that you want. Yes?
This is AG3, but like Evolution, this is a transitional form to AG3 where features are slowly being produced over time. There was a search engine for users back in the beta, as well as a two-way friending system, but I'm not sure whether or not these features will be implemented soon.