The Gray
Square

Swipe. Swap. Solve.

A minimalist puzzle about carrying colors across a 7×7 board. Wherever the gray square lands, it trades the color it is carrying for the color already there.

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343 BOARDS 7 SHAPES NO ADS

The level list: seven sets of seven, gold tiles for levels cleared at par.

A level in progress: a 7×7 board of colored tiles, the goal row outlined, two cells already ticked green, and the gray square waiting below the board.

How it plays

Think three moves ahead.

Every move fixes one cell and disturbs another. Try it — a real 7×7 board with a three-cell goal and a par of 9.

Goal

0 of 3

Moves

9 left for par

1

Swipe to move

The square starts just below the board, carrying nothing, and slides one cell per swipe.
2

Landing swaps colors

You drop the color you carry and pick up the one under you. The very first move is free — with nothing in hand, you simply pick a color up.
3

Fill the goal cells

Only a handful of cells are marked. The rest of the board is your workshop: a place to park a color you will need in four moves' time.

Par, keys and gold

Beat the par. Earn the gold.

Every board has a solver-checked best score. A solution is really a delivery route, and par is the length of the shortest one.

Par and the move budget

Par is the fewest moves the level can possibly be solved in — 4 to 25, depending. Past the move budget, a clear no longer counts for anything.

The move meter under the board tracks you live. A sloppy replay can never cost you a record: the save keeps your best run, not your last.

Clear the board. Earn a key.

Clear a level and you get a key. Clear it in par and you get two, plus a gold tile on the level list. Keys open levels — and that is all they do.

A key opens any locked board whose left or upper neighbor is already open, so a board you cannot crack never blocks the rest. You start with three; key packs are the game's only purchase.

The boards

343 boards. Seven shapes.

49 boards per shape, presented as seven sets of seven. A bigger shape is not simply a harder one — a three-cell line with its colors scattered to opposite corners can outlast a thirteen-cell cross whose pieces happen to be nearby.

Horizontal49 boards

Vertical49 boards

Cross49 boards

Diagonal49 boards

L49 boards

Square49 boards

Triangle49 boards

Accessibility

Made for every eye.

Seven playable colors on one board is a real accessibility problem, and the palette is hue-only. Colorblind symbols and goal outlines are built in — both toggle mid-level and take effect immediately.

Colorblind symbols — every color also carries a distinct shape, on tiles, on your square and in the goal map, so pairs that collapse under red-green CVD stay tellable apart.
Outline goal cells — rings the cells still to fill and badges the ones already right. Left off, the board stays silent about the goal beyond dimming the cells that are not part of it.

Cloud save

Your progress travels

Progress is saved locally first, so an offline phone never loses a thing. On iPhone and iPad it also restores through iCloud; on Android, sign in to Google Play Games and it syncs there.

When a device and the cloud disagree the two are merged rather than overwritten — unlocked levels combine, the better move count is kept, and a spend on one device cannot come back as extra keys on another.

Machine-verified

Where the numbers come from

A customized A* search solves each candidate board and returns its optimal move count, which becomes par. The heuristic estimates a lower bound from transport cost — how far each wrong cell's correct color has to travel to reach it.

Boards that cannot be solved, or that solve too cheaply or too expensively, are discarded. Every level in the game is known to be solvable in the count printed on it.

Screenshots