Galaxies puzzle rules

Divide all cells into connected regions. Each region contains exactly one numbered center and has 180° rotational symmetry around it.

Find the opposite cell

Imagine a cell turning halfway around its center. The cell it lands on must be part of the same region. A region cannot own a cell whose opposite would fall outside the board.

A center at a grid intersection

A center where four cells meet belongs to all four touching cells. Each 2 × 2 region in this separate rule example matches itself after a half-turn.

Keep one region per center

Region cells connect through shared edges. A corner touch alone is not a connection. The cells touching a center are fixed to that galaxy, so another region cannot contain that center.

Assign cells

Choose Galaxy 1, Galaxy 2 or another numbered button, then tap cells to assign them. The same number appears in the assigned cells, so colors are not needed to identify regions. Boundary lines appear between differently assigned neighbors.

Arrow keys move. Enter or Space assigns the selected galaxy. Number keys assign that numbered galaxy to the selected cell. Backspace or Delete clears an unfixed cell. Center cells stay fixed. Undo removes one assignment; Restart clears only this board after confirmation.

Hints and daily play

Hint gives one proved region assignment. Apply this step enters it. Conflicting assignments must be undone before a valid hint can continue. Daily boards use a separate original set and are fixed for the UTC day. All twelve practice/daily boards have one solution.

Nikoli’s Tentai Show rules and Simon Tatham’s Galaxies rules were used to check connected regions and half-turn symmetry. Orbitwoven’s center layouts, diagrams and interface are original.