Complex sentence: He flew into space and encountered the Space Core and Wheatley who are then run over by the U.S.S. Enterprise, was challenged to a race by a cartoon Pop-Tart cat.
Split into simpler sentences: He flew into space and encountered the Space Core and Wheatley who are then run over by the U.S.S. Enterprise. He was challenged to a race by a cartoon Pop-Tart cat.