Complex sentence: The developers found that 90% of players make positive decisions, and prior to playing the game, young boys found the concept of girls playing soccer controversial; after, nearly 90% "agreed that girls can play soccer".
Split into simpler sentences: The developers found that 90% of players make positive decisions. They also found that, prior to playing the game, young boys found the concept of girls playing soccer controversial; after, nearly 90% "agreed that girls can play soccer".