Sudoku and Spiral Galaxies are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Spiral Galaxies is distant to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: Rectangular
- Closeness to Sudoku: Distant
- Also called: Tentai Show, Galaxies
What is Spiral Galaxies?
Divide the grid into regions, each with 180° rotational symmetry about a given centre dot. Here are the rules in full:
- Every cell belongs to exactly one galaxy.
- Each galaxy is rotationally symmetric — unchanged by a 180° turn about its dot.
- Each galaxy contains exactly one dot.
See a Spiral Galaxies grid
Spiral Galaxies divides the grid into regions, each with 180° rotational symmetry about a given centre dot. Below, two galaxies, each symmetric about its dot.
Two galaxies (colours), each rotationally symmetric about its centre dot.
Both partition the grid into regions by logic alone, and both progress by ruling out which region a cell can belong to. But the regions are defined by rotational symmetry, not by holding a set of digits, and there is no row, column or number rule — a distant relative.
What Spiral Galaxies shares with Sudoku
- Both partition the grid into regions under strict rules, by logic alone.
- Both progress by ruling out which region a cell can belong to.
How Spiral Galaxies differs from Sudoku
- The regions are defined by rotational symmetry, not by holding a set of digits.
- There is no row, column or number rule at all.
Do Sudoku skills transfer?
No technique carries over, but the "which region can claim this cell?" elimination is close kin to Sudoku candidate elimination.
The verdict
Spiral Galaxies is a symmetry-based partition puzzle that shares Sudoku's elimination logic, not its numbers.