An Irregular Sudoku grid with a non-contiguous region is possible, but usually there can be only one, else how to determine to which region the errant cells belong? I’ve kept these connected, albeit tenuously, and the resulting shapes seem like botanical pixel art.
Rules:
Normal Irregular Sudoku rules apply. (There are nine regions of nine cells each, but they are not 3x3 squares.)
Cells separated by a chess Knight’s move do not contain the same digit.
Digits within circles appear at least once in cells touching the circle.
Digits on gray palindrome lines make up the same sequence in either direction along the line. The center of each line is indicated.
Estimated difficulty: 1.5 out of 5
Solve on SudokuPad