Complex sentence: Answering enough questions to complete the contract gained the couple control of their respective archway, but if they did not Garagiola moved to the top level and asked the remaining questions to the other couple.
Split into simpler sentences: Answering enough questions to complete the contract gained the couple control of their respective archway. Failing to complete the contract passed control to the opposing couple, and Garagiola asked the remaining questions to the other couple.