Good idea, but the rules were a bit hard to understand. They needed some proofreading. Also, graying something out is usually used to convey "this item is not active". So, I'd recommend reversing the colors of the check mark. However, this game makes me nostalgic for those old Adobe Flash card games. Add some art, sound, and animation along with a win/lose state, and you'd have a pretty solid way to kill some time. Additionally, I like the alternative strategy of trying to score low. And, adding the chance for a win through matching a sum was a good idea.