If the game isn't changing the physics to force you to watch ads to gain more lives to continue to play, or get power ups to beat certain levels, then it is doing so to try and force you to purchase said necessary items. It is extremely limited, if you don't open you wallet or cheat. And the pvp arena is filled with cheaters who will double, triple or quadruple the "perfect score" so you get penalized for it. They actively try to charge you for ruining everything that made the original great.