Inside OS X 10.8 Mountain Lion GM: Game Center and Chess 3.0
A preview in Chess 3.0
Apple's bundled Chess app, however, has been updated to support Game Center features. It also has some other minor updates, including a "gloss" background and subtle changes in its preferences. The computer AI, for example, now lets you choose specifically how many future moves (or how much time) the computer will ponder before making its move. Previously, Chess just presented a slider from "faster" to "stronger."
When you start an Game Center-enabled game, it logs into the network for you if you've already configured your account in Game Center. Otherwise, it will prompt you to sign in.
Signing into Game Center within Chess gives you access to two new features in the new 3.0 version, starting with Game Log, which in Chess shows the series of moves made. In the game below, an Achievement was also unlocked by putting the opponent's king in check.
Specific Game Center Achievements that have been unlocked can also be listed in the new Chess 3.0 (below), providing an additional way for players to meet secondary challenges as they play a game.
These Achievements are also tracked in Game Center itself, along with a list of players you have shared games with (below).
Cross platform Game Center play
Apple won't allow developers to list their own Game Center apps in the App Store until Mountain Lion ships, but it has already paved the way for developers to not only have Mac Game Center titles available at launch, but also to produce multiplayer titles that users on both iOS and OS X can play together.
Additionally, Apple has created a new Groups feature to allow users to share achievement and leaderboard score data between apps, enabling a developer to make a user's achievements visible across a connected franchise of related apps, or across the platform-specific versions of its game.
"With the Game Center app on your Mac [in OS X Mountain Lion], you can play anyone on a Mac, iPad, iPhone, and iPod touch," Apple notes, adding in a footnote that "Game Center is available on iPad, iPhone 3GS or later, iPod touch (3rd generation and later), and Mac computers with OS X Mountain Lion. Game Center works with games that have been developed to work with the Game Center service. Game Center may not be available in all countries or regions, and the available games may vary by country or region."