Nurikabe

Shade cells as sea so every numbered island has the correct size.

Rules

• The numbered cells are island clues and are always island cells.
• Each island must contain exactly one clue.
• The size of each island must match its clue value.
• Sea cells must form one orthogonally connected region.
• A 2x2 block of sea cells is not allowed.

The puzzle is solved when every sea cell is marked and all rules hold. Any remaining undecided non-sea cells count as island.

Controls

Key	Action
Arrows / wasd / hjkl	Move cursor
x	Set sea
z	Set island
Backspace	Clear to unknown
Ctrl+H	Toggle full help
Ctrl+R	Reset puzzle
Escape	Return to main menu

Mouse

Action	Effect
Left click	Move cursor, or set sea on the current cell
Left drag	Paint sea from the current cell
Right click / drag	Set island cells

Tips

• Start with clue 1 islands; all neighbors must be sea.
• Avoid 2x2 sea early, it removes many wrong branches.
• Track unfinished islands and reserve room to reach clue size.