Normal sudoku rules apply. Along the green line, adjacent digits must differ by at least five.
The clues outside the grid are sandwich sums: each gives the sum of the digits between the 1 and 9 on the indicated diagonal.
The base paths are double arrows: the digits on each path have the same sum as the bases at the ends of the path. The bases contain four different digits.
Online solver: SudokuPad
(If you don't want to deal with the diagonal layout, here's a regular orthogonal grid: SudokuPad)
Lösungscode: The upper-right-most diagonal, from the top corner to the right corner. (In the orthogonal version, this is column 9.)