Game: Add Initialize method.

git-tfs-id: [https://tfs.codeplex.com:443/tfs/TFS15]$/Atomix;C39552
Game: Add levels button to home screen.

git-tfs-id: [https://tfs.codeplex.com:443/tfs/TFS15]$/Atomix;C39553
Game: Levels selection.

git-tfs-id: [https://tfs.codeplex.com:443/tfs/TFS15]$/Atomix;C39554