(This post is part of the Genuinely Approachable Sudoku (GAS) series.)
Besides the standard Arrow Sudoku rules, in this grid there must be …/even/odd/… alternation in each cell from the bulb to the tip of the arrow.

PDF

or solve online (using SudokuPad)

Theme: Not an Arrow Sudoku

Author/Opus: This is the 121st puzzle from Clover, part of the Genuinely Approachable Sudoku (GAS) team.

Rules: Standard Sudoku rules (insert a number from 1 to 9 into each cell so that no number repeats in any row, column, or bold region). Some arrow shapes are in the grid; the sum of the numbers along the path of each arrow must equal the number in the circled cell. Also, along each arrow shape, the numbers (including the circled cell) alternate in parity. (For instance, 9 = 2 + 7 and 9 = 4 + 3 + 2 are valid sequences, but 9 = 7 + 2 and 9 = 1 + 3 + 5 are not.)

GAS Time Standards (highlight to view): Two party hats (🎩🥳): 6:30; One party hat (🥳): 12:00. All other solvers earn a 🦕: forgot-a-constraint Fabrosaurus.

Thomas Hits the GAS (highlight to view): 2:13, with SudokuPad replay file shared as a download for now (requires loading via settings menu with improvements expected before people should use this regularly).

Solution: PDF; solving video with explanation to be added later from GAS team.

Note: Follow this link for other Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in these books in our e-store.

Note 2: Comments on the blog are great! For a more interactive discussion, please also consider using our Daily GAS discussion post on the GMPuzzles Discord. Not a member of the Discord? Click this link for basic access.