Complex sentence: When time was up, the players with the three highest scores went on to play the "Cryptic" round, where the answers appear one letter at a time, and the contestants were given a clue to each word.
Split into simpler sentences: When time was up, the three highest-scoring players entered the "Cryptic" round. In this round, the answers appeared one letter at a time and the contestants were given a clue to each word.