or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)
Author/Opus: This is the 364th puzzle from our contributing puzzlemaster Grant Fikes.
Rules: Shade some empty cells black to create a single connected group. Cells with circles cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid. Each numbered cell indicates the total count of shaded cells connected vertically and horizontally to that numbered cell.
Difficulty: 1 star
Time Standards (highlight to view): Grandmaster = 0:35, Master = 1:00, Expert = 2:00