title: sprite kit swift initial slow frame rate/ lag?
body: <p>I've just started learning how to use sprite kit, I've almost completed my first game, however I have come across a problem which I don't really know how to solve, basically when I first load the game/scene the game is very laggy FPS drops to about 30, and movement and animations are not smooth, however soon as the first scene is finished and play again everything is super smooth? so initial load is slow, second and every load after that is fine, I need some pointing in the direction, thanks </p>