I really like this video. I do want to let y'all know something about the challenge thingy, so you don't make the same mistake I've made. If you challenge a card, you're saying that they don't have the color of the card before it. For example, if there's a blue down and someone puts down that card and changes it to red? If you challenge and win, that means that they changed the color even though they had a blue in their hand.