As the series title suggests, 'Usborne Puzzle Adventures: Advanced Level', are puzzle books for those interested in more complex, time-consuming puzzles.

More Complexity

Books still hold an exciting story but are more in-depth, text-wise, and contain 'fiendish codes and puzzles which must be solved to unravel the plot.' Readers are warned: "Most of the puzzles are pretty difficult, so don't be surprised if you get stuck. [...] If you don't to look at [the clues], you may well be a genius."

Books seems mainly centred around navigation puzzles or deciphering complex codes and messages (roughly half of the puzzles in some books were difficult codes to be decrypted). Some series regulars returned to write and illustrate this series, with only 3 titles, and created a strong array of characters and puzzles.