Logic Masters Deutschland e.V.

- Normal sudoku rules apply: Each row, column and 3x3 box contains the digits 1 to 9.
- Nonconsecutive rule applies: Orthogonally adjecent cells must not contain consecutive numbers.
- Odd-even rule applies: Cells with grey circles must contain odd numbers, cells with grey squares must contain even numbers.

(The colors are purely cosmetic.)

Try the puzzle on F-Puzzles: colored or uncolored. Good luck! / Glück auf!

Author's comment (contains some, though not too helpful, hints for solving the puzzle)
This puzzle is a bit of a slog. It involves a lot of hard work of eliminating possibilities by thinking a few steps ahead only to be barely rewarded for it. This made me think digging through rocks and sifting through dirt in search of valuable materials. Thus, the puzzle is titled The Mine. Blue represents the sky, where the given digits "1, 2, 3" indicate the direction of our solve. From there we dig past the green grass into the reddish-brown earth below for our first digits (the squares and circles create a rocky/earthy texture). We mine the earth for digits and pencil marks, until we have enough information to resurface. Once we start putting digits above the earth (perhaps us returning with a few spoils to sell in exchange for better equipment) we are in the clear and the rest of the puzzle resolves itself without much difficulty.
I give the puzzle a four star difficulty rating for the back-breaking work, though no particularly advanced sudoku-magic is needed. I would be happy to receive your feedback - on the difficulty rating specifically as well as in general. I hope you enjoy(ed). :)