Game Center was originally announced at an Apple iOS event on April 8th, 2010. A preview was later released to developers in August. Game Center was billed as one of the "7 tent-poles" of iOS 4.0, but did not end up shipping with the final build of the OS.
Game Center was released on September 8th, five months after it was originally announced. It was part of the iOS 4.1 update. Game Center is supported on all iPhones and iPod touches, except the iPhone 3G.
Features of the Application
Game Center is a core app (unable to be deleted) that acts as the hub for friend invites, as well as being able to browse through your Game Center-enabled games.
Upon first use, one must create an account using their Apple ID. The app will prompt for basic information, and then will ask for a nickname, which is the name people will find you by.
The app is divided into 4 main categories. The home page is for the profile, and shows the nickname, number of friends, number of Game Center games, and number of achievements. There is also a field for a slogan or motto of some sort, and at the bottom one can manage the technical aspects of their account.
The "Friends" page is next, which shows what games your friends are playing and allows you view their profiles for more information about their games. One a friends page you can see their Game Center stats (# of friends, games and achievements) as well as games that you have in common with them. You can also compare scores and achievements with your friend.
The next page is the "Games" page. From this page you can see all of your Game Center games, with how many achievements you have unlocked, as well as overall ranking. Tapping a game will allow you to see detailed information about that particular game like leaderboards, achievements, and players that you have recently played against.
The last page is for "Requests". You must approve each friend. You can find other friends by either sending them an invite by entering their nickname, or their apple ID email. As with Ping (Apple's music social network integrated in iTunes) there is no Facebook or Twitter connection at this time.
Features in Games
While playing a Game Center-enabled game, you can view the achievements and leaderboards from the game's menus. Achievements will pop up upon completion.
One of the biggest advancements Game Centers brings is multiplayer matchmaking and invites. However, there is a very limited amount of Game Center-enabled multiplayer games; even games that have been updated with basic Game Center support, like Real Racing, do not feature online multiplayer.
Pangea Software had the first multiplayer Game Center games: Cro-Mag Rally, a cart racer released in 2008, Nanosaur 2 a flying-combat game set in pre-historic times, and Enigmo 2, a fluids based puzzle game.
The pre-game set up is all done through the in-game menus, but one all of the settings have been confirmed, the Game Center UI pops up, giving you the option of opening up player-slots (to a maximum of 4 total, including you). You can invite friends to the lobby, or let Game Center match-make to fill up the slots.
Voice chat is also a staple of Game Center multiplayer, and the mic can be muted/unmuted by a button on the top left side of the screen.
The multiplayer information is based off of the current multiplayer games available. As more developers update their games, we will have more accurate information about what type of multiplayer experiences Game Center can provide.