Galaxies is one of Simon Tatham's portable puzzles. The grid is scattered with dots. Draw edges along the grid lines to split it into regions so that each region contains exactly one dot and looks the same when turned half a turn around that dot.
Every puzzle is generated fresh, in several sizes and difficulties, and can be solved by logic alone.
Controls
Click or tap an edge between two squares to add or remove a line. The menu bar has New game, Restart, Undo, Redo and Solve; Type changes…
Genre
Puzzle, Logic, Desktop
Price
Free — no account, no download, nothing to install
Tips for Galaxies
Squares right next to a dot belong to that dot's region, and so do their mirror images.
Draw lines between squares you know belong to different dots.
Small regions around corner dots are often the easiest start.