- (IBAction)leaderboardsClicked:(id)sender{
    GKGameCenterViewController *gcViewController = [[GKGameCenterViewController alloc] init];
    gcViewController.gameCenterDelegate = self;
    if (gameCenterEnabled) {
        gcViewController.viewState = GKGameCenterViewControllerStateLeaderboards;
        gcViewController.leaderboardIdentifier = @"blockfall_scores";
    }else{
        gcViewController.viewState = GKGameCenterViewControllerStateAchievements;
    }
    [self presentViewController:gcViewController animated:YES completion:nil];
}