I beat the game! It's harder to remember the colors, of course, but considering the enemy isn't very smart, it was easy.
The cards flip too quickly. I think if you slow down the cards and make the enemy a little stronger, it'll be fine.
When there are so many sprites at the beginning, it's really hard to remember the images.
It's also sad that the bot plays rather poorly—if you, as a player, make obvious mistakes and clearly highlight identical cards, the bot never exploits these weaknesses and doesn't even notice when it opens cards successfully. Personally, it only managed to pair me a few times; I can't imagine how long it would take for the bot to win.
But the idea is original, and the execution is decent. Good job!