These arrows keep aiming for those quadruples, but missing. They’ve got the aim of Star Wars stormtroopers.
Also, this is the 100th puzzle posted to this blog! (Internally, it’s puzzle 2630.)
Rules:
Normal Sudoku rules apply.
Digits within thin circles appear at least once in cells touching the circle.
Digits along arrows sum to the digit in the attached thick circle.
Estimated difficulty: 1 out of 5
Solve on SudokuPad