Memory Match is a game where you try to match pairs of cards together in as few moves as possible. The twist is, you can't see the cards, so you have to keep it all in your head (or cheat with a piece of paper). You start with 12 cards face down, laid out in 4 rows of 3 columns. Each turn you first guess one card by saying "row 1, column 2" and you'll be told what's on the card, for example "red square". Next, you'll choose a second card, "row 4, column 1". If the second card matches the first they make a pair. Once you've figured out all 6 pairs, you win.
Note: If you've turned on the 'start of request' tone in the settings for your Alexa device, you may experience problems with it recognizing your responses. You can switch it off by going to the Alexa app then Settings -> [your device name] -> Sound & Notifications and ensuring the switch for 'Start of Request' is in the off position (left, with the switch colored white).