A logic puzzle of hidden ghosts
Find the ghosts hiding on the board, using nothing but the numbers.
Nothing is left to luck — all 2,000 puzzles solve by reasoning, start to finish.
Ghosts are hidden somewhere on the board. All you can see are numbers.
Read them and the board resolves a cell at a time — this one is empty, that one has to hold a ghost. You never tap and hope. Every ghost, down to the last, is found for a reason.
Reveal a cell with no ghost in it and you lose one of three lives. Lose all three and the puzzle starts over — you lose the moves, never your progress.
Your first time in, you start on a tutorial board that walks you through it — each move, and the reason for it — so you can start without reading any of this.
EASY through ULTIMATE, with boards growing from 4×4 to 9×9. There is no timer — nothing rushes you. A small board takes a few minutes; a large one takes as long as you like. Every puzzle is saved on its own, so you can go a little at a time.
The first 160 puzzles — EASY — are built entirely from moves where a single number gives you the answer. Later sets add new kinds of move: comparing two numbers, then assuming a ghost is somewhere and finding the contradiction. The boards grow, but that isn't where the difficulty comes from.
Every technique is written up in the Tips library, one at a time, illustrated on a real board.
Line your moves up so several conditions complete at once and the score jumps. A puzzle that isn't hard to solve becomes something else when you go for full marks.
Keepy, Mimo, Zuzu, Piri and Tobi — the Keepyboos. They chatter away beside you while you think. Keep going and more of them turn up, along with new wallpapers and sounds.
The numbers read the same way. Very little else does. One wrong tap doesn't end the board — there are three lives. Nothing comes down to a coin flip: every one of the 2,000 puzzles has been checked to solve by reasoning alone, all the way to the end. And rows and columns carry totals too, so you can work the whole board at once.
EASY, NORMAL, HARD, EXPERT and MASTER — 1,110 puzzles — are free, with no time limit and no play limit. Past those, EXTREME (690 puzzles) and ULTIMATE (200) are paid, and the first 20 and first 10 of them are free to try. Beyond that, you can buy the ads away, and some of the wallpapers and sound sets are for sale (others are earned by playing). Everything is a one-time purchase. There is no subscription.
In two places: occasional ones between rounds, and a video when you ask for a hint. The hint button is marked “Ad”, so a video only starts when you tap it (we ask once, the first time). You can buy the ads away.
Yes. A connection is only needed to show ads and to back your progress up.
Progress backs itself up automatically. Link a Google account in the settings and it comes with you to a new device.
Fourteen: English, Japanese, German, Spanish, French, Indonesian, Italian, Korean, Portuguese, Russian, Turkish, Vietnamese, and Chinese (Simplified and Traditional).