Logic Masters Deutschland e.V.

The puzzle: https://f-puzzles.com/?id=y7cx9kme
The solve by Mark Goodliffe: https://www.youtube.com/watch?v=y1NSNMKbE2w

"Rainbow Horse in the snow breaking through the fence"

Or in short, Rainbow Horse!

This puzzle is metaphorical for the times we are living in. The snowy winter stands for the dark and sad times with this pandemic and the fence is a metaphor for people who are locked in their homes with curfew and fines. But as the rainbow stands for creativity and cheerfulness, this wild horse can't be tamed and breaks through the fence by creating and solving Sudoku puzzles!

Normal Sudoku rules apply. On top of that:

• Digits along an arrow in the grid must sum to the digit in its circle.
• Along thermometers, digits must increase from the bulb to the end.
• The grey line is a palindrome, it reads the same from both directions. Each different digit must appear at least once on the palindrome.
• The black dot means that the ratio of the two connected cells is 2.
• The white dot means that the difference of the two connected cells is 1.
• In cages, digits must sum to the small clue given in the top-left of the cage.
• There are no negative constraints.