I enjoy combining polyominos with grid-deductions. My current plan is to create a Pentomino Nurikabe. But that sounds hard, so I made this Tetromino Nurikabe as practice first. I think it came out well, so here goes!
Rules: (Nurikabe section shamelessly stolen from an earlier puzzle by @jafe)
- Numbered cells are unshaded.
- Unshaded cells are divided into regions, all of which contain exactly one number. The number indicates how many unshaded cells there are in that region.
- SPECIAL RULE: the regions will form a tetromino set, with rotation and reflection allowed.
- Regions of unshaded cells cannot be (orthogonally) adjacent to one another, but they may touch at a corner.
- All shaded cells must be connected.
- There are no groups of shaded cells that form a 2 × 2 square anywhere in the grid.
I've included all available tetrominoes as a reference.
,,,4,,, ,,,,,, ,,4,,,, ,,,,4,, ,,,,,, ,,,4,,, ,,4,,,,