The challenge comes in obtaining a diamond or gold rank in levels. Obtaining silver on most levels is easy, really easy. If you want to raise the difficulty aim for a gold rank in levels. If you truely want to challenge yourself aim for a diamond rank.
New update has been out. Review sent. I tried the new addition on both iPad Air 1 and 2 devices, but lost many power ups because the game would freeze and crash during online tournaments. Please look into this and fix asap.
