Nurikabe: Island Logic Puzzle

Nurikabe (also known as Islands in the Stream) is a relaxing Japanese logic puzzle. Paint the walls, leave the islands — every puzzle has exactly one solution, found by pure deduction, never by guessing. What is Nurikabe? Nurikabe (ぬりかべ, "painted wall") is a classic Japanese logic puzzle from the makers of Sudoku, Nikoli. The rules are simple, the deductions are deep: • Paint cells to build one connected wall; leave the rest white as islands. • Each numbered cell belongs to exactly one island whose size equals the number. • The wall must stay a single connected shape, and no 2×2 area may be solid wall. • Islands may only touch diagonally — never side by side. Every puzzle in this app has exactly one solution and is solvable by logic alone — never by guessing. Three ways to play • Journal — 1,200 hand-picked levels across 100 pages of a stamped, stationery-style journal. Solve a page, earn its stamp. • Free play — pick any size from 5×5 to 12×12 and solve at your own pace, no limit on boards. • Survival — solve puzzle after puzzle to buy time before the ink dries. Chase your best run on the worldwide leaderboard. Features • 1,200 hand-picked levels, plus unlimited free-play boards from 5×5 to 12×12. • A stamp case of 15 achievements — from your very first solve to survival close calls. • A live-clock survival mode with a worldwide leaderboard. • Full offline play — no internet required, no account, no nag. • A quiet, stationery-inspired look in light and dark, that follows your system. • High-contrast mode and a colour-blind-safe palette. • Cell states distinguished by shape AND fill — accessible by design. • Smart hints when you're stuck (opt-in, never forced). • Undo / redo and an auto-save that resumes exactly where you left off. • Pinch-zoom and pan on large grids. • Localized in 32 languages with proper font support for CJK, Arabic, Hindi, Thai and more. • A small download — nothing to wait for. Calm by design — and rating-safe • No ads while you solve. Ever. The play screen has zero ad chrome. • Journal and Free Play have no timer — solve at your own pace. • A gentle completion celebration, then straight back to the page. • Optional sound and haptic feedback that you can fully disable. Brain training that travels with you A logic puzzle is one of the best low-effort habits for keeping your mind sharp. Nurikabe works on the bus, on a flight, in waiting rooms — anywhere, offline. Free to play Nurikabe is free. An optional one-time "Remove ads" purchase removes the completion-screen interstitial. Survival's pen refill — an optional rewarded video, once per run — stays free for everyone. Paint the walls, leave the islands. Free to play.