A reaction/memorize your cards type of game.
Karta Challenge is primarily designed for two (or more) participants, but you can also compete against CPU-Players.
Try to tap the shown card before your opponent does. But beware: The card may not be on the playing field. The fastest player wins.
Besides a quick match, you can also play in finals (up to sixteen players) with random
pairings and in a league (three to six players), in which everyone plays against all others.
You have the choice of five different set of cards. One of them is a math cardset, in which you have to pick the corresponding card to a (not always) simple arithmetic problem.
There is also a lite version of Karta Challenge for trying out the game.