I love the idea, but there's a couple things which are slightly broken.
- Might just be my luck but too often there are no groups in the deck. This might also just be my skills in the game so feel free to disregard this point.
- Sometimes the cards don't show as selected and this required refreshing the page. Bit strange, and I can't find the cause.
When it works, it's a great puzzle game and I love it!