Soldoku: Light Logic Puzzle

What is Soldoku?

Soldoku is a logic puzzle about light: place suns on the board to light up every tile. Each numbered stone tells you exactly how many suns must sit right next to it — no more, no less. Every level has exactly one solution you can deduce. No guessing, no luck involved.

How to play
• Tap a tile to place a sun. Its light travels in a straight line until it hits a stone.
• Two suns can never see each other on a solved board — try it, and the game simply won't let you, catching contradictions before they happen.
• A stone marked "2" needs exactly two suns among its neighbouring tiles, no more, no less.
• Light up every tile with each stone at its exact number of neighbouring suns, and the level is solved — no partial score, no ambiguity about whether you got it right.

No punishment, just puzzle
• No lives, no game over, no timer working against you.
• Undo any move at any time by tapping the same tile again.
• Nothing you do is final until you decide it is.
Soldoku is built for anyone who wants a logic puzzle they can think through at their own pace, not one that punishes a wrong move.

Daily Challenge and streak
Alongside the main path, Soldoku has a separate Daily Challenge: a fresh puzzle every day, the same one for every player. Keep your streak alive by playing each day — miss one and the streak resets, but nothing you've already unlocked on the main path is lost.

Climb the rankings (optional)
If you want, connect with Google Play Games to see how you compare with other players, both in the Daily Challenge and overall, with your own animation as you climb the leaderboard. It's entirely optional — Soldoku plays start to finish with no account at all.

A journey through different landscapes
Soldoku's level path isn't the same board repeated: it moves through different settings, each with its own mood and small living details — a spring meadow full of tiny flowers, a quiet village, a path between hills, a calm lake with lily pads, a forest that changes colour with the seasons, and more places that will keep being added as the path grows.

Learn by doing
A guided tutorial points to exactly which tile to tap and explains why, step by step, then lets you solve levels on your own. No manual to read first, no rules to memorize — and a Skip button if you already know this kind of puzzle.

Who it's for
Soldoku is for anyone who enjoys a calm logic puzzle: fans of Akari (also known as Light Up) and other grid deduction puzzles like Picross, anyone looking for something relaxing to think through on a commute or before bed, or anyone tired of games that punish a wrong move instead of just letting you try again.

Respectful by design
• Fully playable offline, with no account — your progress lives on your device.
• Undo freely at any time: nothing you do is irreversible until you want it to be.
• No lives system, no energy bar, nothing that makes you wait to keep playing.

Whether you have two minutes or twenty, Soldoku rewards thinking calmly over rushing: pure logic, no shortcuts, no pressure.