Playing Uno on Xbox Live Arcade will teach you a lot of things you didn't know - namely, how to play Uno. Most people remember the basics: ditch all the cards in your hand to win, but you'll need to sidestep the Skip and Reverse traps while avoiding the deadly Draw Two and Draw Four cards. But whether they know it or not, most people play with house rules, like drawing cards until you get one you can play or adding two Draw Two cards to make the next poor bastard draw four.
Thankfully, the Xbox Live edition embraces many of those weird "that's not the way we played it in my family" variations and lets you activate them at will. If you want to be ranked on the Live leaderboards, you'll have to play it straight, but for more casual games, go nuts with your favorite rules (or alternate card sets - there's a free 35th anniversary deck download available already, complete with its own rule tweaks). Voice chat keeps the fast-paced game friendly, and while Uno supports the forthcoming Xbox Live Vision camera, that doohickey was not available for our review (and plugging in a normal webcam did nothing).
The computer-controlled players try so hard to be human that they are programmed to forget to shout "Uno!" when they've got one card left - a little too often to feel real, actually. Otherwise, this is a classy, clean implementation of an old favorite that feels instantly comfortable - and, amazingly enough, at 400 points ($5), it costs about three clams less than a real deck of Unocards.