Mahjong solitaire

A matching game with tiles you can read: every tile shows a big number or letter, and every game can be won.

The aim

Clear the table by taking the tiles away in matching pairs.

The tiles are piled up in layers, like a little building. The classic layout, the Turtle, has 144 tiles in five layers.
Tiles in higher layers are drawn a little up and to the left, and you can see the thickness of each tile, so you can tell which tiles sit on top of others.
Each kind of tile appears four times, so there are two pairs of each.

Circles (blue), bamboo (green) and characters (red) are numbered 1 to 9. The number is printed big in the top corner, with a picture of the suit under it.
Winds show a big letter, E, S, W or N, with an arrow pointing that way.
Dragons show one large picture: a red one, a green one, and a blue frame for the white dragon.
Flowers (a purple flower) and seasons (a brown sun). Any flower matches any other flower, and any season any other season, so they all look the same.

Two tiles match when they look exactly the same.

Find a tile that is free. A tile is free when no tile lies on top of it, even partly, and its left side or its right side is open. Free tiles have the brightest faces; the others are a little greyer.
Tap the free tile. It turns yellow, and the free tiles that match it get a dashed blue frame.
Tap one of the framed tiles. Both tiles are taken away.
Taking tiles away frees others. Keep going until the table is clear.
To let go of a tile you tapped, tap it again.

Every game is dealt so that it can be won, but the order you take the pairs in matters. If no free pair is left, you have two choices:

Tap Undo to take back moves, and try a different pair.
Tap Shuffle, which appears at the bottom of the screen. It mixes up the tiles that are left into a new position that can still be won. Undo puts them back if you change your mind.

Turtle, the classic: 144 tiles. Best on a computer or a tablet. Play the Turtle.
Pyramid: 80 tiles, eight across, so it fits a phone held upright in large print. Play the Pyramid.

Work on the tall piles in the middle and the long rows early. Tiles at the ends of rows are easy to reach later.
When three or four matching tiles are free, think before you take two of them: leave the ones that are blocking other tiles for last.
Look under a tile before you take it: taking the right pair can free two new tiles at once.

Undo takes back any move, as many as you like.
Restart sets out the same game again; New game deals a different one. Each game has a number, shown at the top of the screen, so you can play it again.
With a keyboard, the arrow keys move between tiles, Enter picks a tile and then its match, and Escape lets go.
There is no timer and no score. Take as long as you like.