In the mailbox of the city-renowned tinkerer workshop of Professor Charlie, you will find 24 mysterious letters that pique your curiosity. There is no sign of Professor Charlie. You embark on a long riddle journey - directly following in the footsteps of the mad professor. Can you solve all the puzzles and trace his travel route? Are you trustworthy and smart enough to learn about Professor Charlie's secret discovery? The puzzle game consists of 24 episodes and can be played all at once or over 24 days, making it suitable as an Advent calendar. If you solve one puzzle each day, it will take you between 5 and 15 minutes. If you play the game in one go, you should plan for about 3-4 hours.