well, as i remember, USA was one of the top countries with very skillful and challenging managers, and a lot active users as well, but they still didn't have that many users as turkey, poland, romania or china. Though it's no surprise to me a lot of users from whole countries chose this game. if they know what they are looking for, here has the biggest chance to satisfy. Because freekick was a very detailed game in terms of tactics, and none of the available games are a match for that, but this one may be a close call, and most of the others i tried are pieces of crap
