Galaxies
One dot in every region. Perfect symmetry around every centre.
How to play Galaxies
Draw lines along the inner grid edges to divide the board into connected regions. Each finished region is a galaxy: it contains exactly one dot, and that dot sits at the centre of the region. Tap one edge to toggle it, or drag across several edges to draw a longer boundary in one motion.
The final test is rotational symmetry. Imagine pinning the region at its dot and turning it 180 degrees. Every square in the region must land on another square in that same region. Dots may sit in a square, on an edge, or at a grid intersection, so always rotate around the precise dot position.
How to spot the next boundary
Start at dots on edges and corners
A boundary cannot pass through a dot. When a dot sits on a grid edge, the squares on both sides must belong to the same galaxy. A dot at an intersection immediately joins all four touching squares. These forced joins are often the fastest place to begin.
Pair every square with its opposite
If one square belongs to a dot, rotate that square halfway around the dot and find its partner. The partner must belong to the same galaxy. If the partner would leave the board or collide with another galaxy, you have found a boundary.
Use colour as confirmation
A correctly closed galaxy fills with colour as soon as all three rules are satisfied. The colour is confirmation, not an extra clue: unfinished white space may still contain several future galaxies. There is no motion while you solve. Once the whole board is complete, every finished region turns 180° around its own dot and lands back on exactly the same cells.
Board sizes from 5×5 to 20×20
Beginner is 5×5, Easy is 6×6, Medium is 7×7, Hard is 8×8, and Expert is 10×10. The game includes 60 generated puzzles. During the build, every answer is checked for connectivity, one centred dot, and exact 180° symmetry; an independent solver then confirms that the visible dots lead to one and only one solution. Progress is saved locally on this device.
The Custom option generates fresh boards from 5×5 all the way to 20×20 on your own device, and every puzzle shows a short code under the board - save the code or copy its link to rebuild that exact galaxy map any time.
Prefer one shared challenge? Galaxies Daily deals the same board to everyone on the same calendar date, with a streak for solving day after day.
Frequently asked questions
What is the goal of Galaxies?
Divide the board into connected regions. Every region must contain exactly one dot, and that dot must be the centre of 180-degree rotational symmetry.
Can a boundary pass through a dot?
No. A dot belongs inside its galaxy. Any line through a dot is shown in red and must be erased.
How do I know when one region is correct?
The game checks it automatically. As soon as a closed region is connected, contains one dot, and is rotationally symmetric about that dot, it fills with colour.
Are the puzzles uniquely solvable?
Yes. Every included puzzle is checked offline by a separate solver using only the dot positions, and only puzzles with exactly one valid partition are published. Custom boards run the same uniqueness check on your device while they generate.
Can I replay a specific puzzle or play bigger boards?
Yes. Every puzzle shows a short code under the board - enter it later to rebuild that exact board. The Custom option generates boards from 5×5 up to 20×20 on your device.