Spiral Galaxies guide
How to solve Spiral Galaxies
Spiral Galaxies, also called Tentai Show, asks you to cut a grid into fields around its stars. Every board has exactly one solution, and one idea about symmetry draws most of its lines. These are the lessons from Polus, the app, played right here on the page.
The rules
- Draw lines along the grid to cut the board into fields. Every field has exactly one star in it.
- A field is balanced around its star: for every square in it, the square straight across the star — the same distance away — is in it too.
- A field is one connected piece, and at the end every square on the board lies in exactly one field.
What a solved board looks like
Tap a grid line to draw a border there, and tap it again to rub it out. Run a finger along the grid to draw or rub out a whole run at once.
1Draw a line
Two stars, so the board needs two fields. Tap the grid line between them.
2One star each
Three stars, so three fields. Draw lines until every star sits alone in its own field.
3Every square has a partner
Look at the two marked squares. The left one holds a star. The right one would need a partner the same distance on the other side of that star — but the board ends there. Draw the line between the two.
4All together
Your turn. Draw the lines so every star has its own field and every square has its partner.
You’re ready
- Every square has a partner across its star.
- At an edge the partner often falls off the board — that settles a line.
- Every field has exactly one star.
That is the whole idea. Big boards are the same partner argument, square after square.