播放按钮需要很长时间才能进入MyScene

Question

    SKSpriteNode *play = (SKSpriteNode*)[self childNodeWithName:@"play"];
    CGPoint location = [touch locationInNode:self];

    if([play containsPoint:location])
    {
        SKScene *PlaneScene =[[abMyScene alloc]initWithSize:self.size];
        SKTransition *fade = [SKTransition fadeWithDuration:1.0];
        [self.view presentScene:PlaneScene transition:fade];
    }

点击播放按钮时，加载游戏大约需要5秒钟。但是当游戏结束并且菜单页面返回时，它会快速加载。我该怎么办？