Complex sentence: Again, he must first battle lesser pirates in order to learn insults, which in this game differ from those used in "Monkey Island 1" in that the insult and the response have to rhyme.
Split into simpler sentences: Again, he must first battle lesser pirates in order to learn insults. The insults in this game differ from the ones in Monkey Island 1 in that the insult and the response have to rhyme.