Complex sentence: In the final round, they pull off a close victory with a decisive final scare by Mike in the simulation bedroom-however, Mike soon discovers that he only won because Sulley rigged the machine to improve Mike's score before he went in.
Split into simpler sentences: In the final round, they pull off a close victory with a decisive final scare by Mike in the simulation bedroom. However, Mike soon discovers that he only won because Sulley rigged the machine to improve Mike's score before he went in.