Genres: Nurikabe, Spiral Galaxies
This is Nurikabe Galaxies, a hybrid of Nurikabe and Spiral Galaxies that I believe originates from Murat Can Tonta, though the precipitating moment for me creating one comes from wormsofcan independently creating it and showing it off.
- Shade some cells in the grid.
- All shaded cells must be connected.
- No 2×2 square can be fully shaded.
- Cells with a circle on any part of the cell cannot be shaded.
- Each connected group of unshaded cells must contain exactly one circle, undivided.
- Each unshaded group must be two-fold rotationally symmetric around the circle it contains. (That is, if you rotate it 180° around its circle, you get the exact same region.)
This was a surprisingly difficult puzzle to make unique, but I think I was able to preserve most of the main argument I came up with.