Вы можете использовать onEnter, onEnterTransitionDidFinish или onExit методы CCNode. Реализуйте методы, о которых вы хотите знать, в своем классе, производном от CCScene.
- (void)onEnter
{
[super onEnter];
/*
* This method is called every time the CCNode enters the 'stage'.
*/
}
- (void)onEnterTransitionDidFinish
{
[super onEnterTransitionDidFinish];
/*
* This method is called when the transition finishes.
*/
}
- (void)onExit
{
[super onExit];
/*
* This method is called every time the CCNode leaves the 'stage'.
*/
}