Level 4 MultiPuzzle. MENTALLY-STIMULATING DOG PUZZLE GAME: The MultiPuzzle by Nina Ottosson is our most challenging dog puzzle yet! This level 4 puzzle requires your dog to complete a series of steps in the correct order to keep discovering more hidden treats! Dog treat puzzles are a great way to reduce boredom and provide mental enrichment for your pup. The MultiPuzzle is perfect for ultra smart dogs that have already mastered levels 1-3.