Dirty Dog $17.99
Level: Difficult
Object: Remove Shaft
A bone to worry for even the most rabid puzzle fans. Even a former US president was bitten by this puppy; ask us about that. (introduced 1985)
Difficult puzzles are very popular because they present a challenge to experienced puzzle solvers, but are more social than the very difficult group. Solving concepts become 'layered', and can involve sequential moves.