Logic Masters Deutschland e.V.

This was a birthday puzzle for Piatato, based on his wonderful Build Your Own Sloop. The rules may look long and complicated but it is pretty simple! See the example images.

Rules:

Shade two cells in each row and column.

Fill the digits 1-8 in each unshaded cell, without repeating a digit in a row or column.

Draw a non-intersecting loop through the centers of all unshaded cells.

The loop must connect to each arrow head to form a valid slingshot clue. That is, the loop must turn 90 degrees in each arrow cell, with one of the loop segments passing through the arrow. Slingshot arrows point from a digit to another instance of that digit, at the arrow cell’s distance.

Clues outside the grid give the sum of the digits between the shaded cells in their corresponding row/column.

Playable sample puzzle and solution: (Penpa, SudokuPad)

In the full puzzle, outside clues are ciphered. Each letter represents a different digit from 0-9. Two digit numbers cannot have a leading 0. A ? represents any single digit.

Links to play:
Penpa+
SudokuPad