If you go to the Japanese Layton website, there is one hidden puzzle!
I will leave two hints below, should you need to spend some hint coins, but it is slightly more enjoyable without the hint, so be careful when scrolling down!
https://www.layton.jp/jouki/en/
Hint 1: Use your mouse, finger or touchpen!
Hint 2: Find the distinctive Silhouette, hidden amongst the members of the crowd!