If you're coming from app development or web development background, you would know that pixels are not same as percentage. So, if the screen is retina, whose scale factor is 2x the normal screen, 500px will appear as 250px, obviously.
I am not using creator right now, so can't give you direct solution but would suggest to read about setting scale factor in cocos creator.
In short, you might not have set your code to scale properly with multiple resolution. So, you might be expecting results as per the normal screen while you tested on retina.. Check with %age dimensions, eg- (50% of deviceHeight), it would work.