Memory
Turn two cards at a time and find every pair. Twelve levels, each board bigger than the last, from four cards to sixty, with thirty pictures in the deck. Clear a level to open the next, or go straight to any size in free play.
All pairs found
Press a card to turn it, then another. A pair stays face up and anything else turns back over. The arrow keys walk the table and Enter turns a card.
How to play
Two cards a turn
Press a card to turn it over, then a second one. If the pictures match, both stay face up. If they do not, they stay up long enough for you to remember them, then turn back. Press the next card and they turn back at once.
Every turn is a move
Two cards are one move, pair or not. Three stars is for clearing a board about as fast as a perfect memory would, two for taking up to half as many moves again, and one for getting there. The stars you are playing for go out as you pass each mark.
Twelve levels, each one bigger
From two by two to ten by six. Clearing a level opens the next and your fewest moves are kept for each. The first five each deal from one part of the deck, fruit or nature or things, and from the sixth on all thirty pictures are in play.
Or skip ahead
Free play opens every board at once, with no stars to earn and nothing locked. The same deck and the same rules, for when the big table is the one you want.
How it is built
No canvas and no game library, like the rest of them. A card is a button with two faces, and turning it is one transition on one property: the layer holding both faces rotates half a turn about its vertical axis, each face hides its own back, and the browser shows whichever one is towards you. The turn overshoots by a few degrees and settles, so it reads as a card with some weight in it, not a square spinning. Every card carries its own perspective, scaled to its size, so a card on the smallest board and one on the largest turn through the same depth.
The thirty pictures are drawn rather than downloaded: one sprite sheet in the page, one symbol per picture, and every card face is a reference to one of them. Each is flat colour on a ground of its own, in three tones: the colour itself, a highlight towards the light and a shade away from it. The pictures keep their colours in both themes and only the grounds follow the page, so an apple remembered in the light is the same apple in the dark. The sounds are made the same way, in the browser, from a few oscillators and a burst of filtered noise, so there is no audio file on the page either.
A card does not know what it is until it is turned. The face-down table in the page holds no answers: the front of every card points at nothing, and the picture is written onto it at the moment it goes over. The deck is shuffled once per board and lives inside the game, where the page cannot read it.
The star marks were measured rather than chosen. A player with perfect memory, one that never turns a card it has already seen unless that card completes a pair, played two hundred thousand games on every board, and three stars is the number of moves it needed in nine games out of ten. Its average came out at 1.61 moves a pair, which is the known answer for this game and how the simulation was checked.
The board is sized to fit the screen, because a memory board you have to scroll is one you cannot see. On a phone held upright it turns a quarter, ten across becoming six across, and not one card moves to do it: the grid fills by column instead of by row, the arrow keys swap axes to match, and a screen reader still walks the same table.