Logic Masters Deutschland e.V.

Rules:

• Sudoku: Every row, column and 2x2 box contains the digits 1 to 4 exactly once.
• Mystery lines: The red, green, and purple lines are mystery lines. Each color is exactly one of the following line types, and no two colors are the same type:
  • Palindrome: digits along the line read the same in both directions.
  • Zipper line: digits an equal distance from the center of the line sum to the digit in the center.
  • Region sum line: box borders divide the line into segments with the same sum.

Solve online: SudokuPad

If you'd like to try a larger and more challenging version of this puzzle, check out Mystery Lines.