The perplexus is one of my favorite maze puzzles!
And also, if you like the Constantin puzzle you bought, buy some of his n-ary puzzpes! They are very fun and long (the shortest is around 20 mins to solve and get it back to the start- if you remember the pattern that is!) . They are super fragile though. Veery fragile, if you buy them, keep them at a top shelf or something so your child wont be able to reach it (when he will be able to

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Greg