Sphere Break requires an analytical or mathematical mindset. Unfortunately, minigames like this tend to single out players, like myself, who are not particularly gifted in one or more of those areas.

I had a difficult time with Sphere Break, but I did not continue with the game until I got Lady Luck. I think that if you watch the Tutorial and challenge Shinra on a consistent basis, you can luck out and receive the Lady Luck Sphere for your troubles.