This is a variation of "Concentration", or "Pairs". The object is to turn over cards (two at a time) to find matching pairs. A timer keeps track of how long it takes to find all the pairs. See below for notes.
Tested with Safari, Firefox and Opera on Mac OS X. According to Browsershots, the page loads and appears to work with Firefox, Chrome, Safari, Opera and Internet Explorer 7 on Windows.
Clicking on a card turns it face up to show its symbol. Click on a second card to see if it matches the first card.
If the two cards picked don't match, they will be automatically turned face down again after a short delay.
If the two cards picked do match, they will be removed from the board (also after a short delay).
The number of attempts refers to how many card pairs are turned over in a game.
An "accuracy" rate is expressed as a percentage. For example, if the player matches 3 symbols after 5 attempts, the accuracy rate is 60%.
The player can start a new game at any time by clicking on the "Start New Game" button or reload the page .
The symbols are actually Unicode characters using the Helvetica font. If the characters are not present on the user's machine, they will appear as rectangles. Earlier versions of Windows in particular seem to lack the necessary characters.
Future enhancements
Support for more browsers, possibly allowing the user to select from common sets of symbols.