The puzzles often seem much more difficult than they are, generally because it can be hard to warp your view of the world to adjust to a place where sword fights are actually fought with insults, where the local cannibals are trying to adjust to vegetarianism, and where the grog which is being happily drunk in the SCUMM bar dissolves away the mugs that hold it. And this is just from the first installment.
Trivia fans will want to know that SCUMM stood for "Script Creation Utility for Maniac Mansion". This is the computer language used to write the adventure.