Here is the full list of all 12 UNO achievements worth 200 gamerscore. It takes around 4-5 hours to unlock all of the achievements on Xbox 360.
Win 40 games of UNO®.
Win ten 4-player games of UNO®, in any mode, on Xbox Live.
Complete a 4-player game of UNO®, in any mode, on Xbox Live.
Play 40 Reverse cards.
Play 40 Draw Two cards.
Play 40 Skip cards.
Successfully play 40 Wild or Wild Draw Four cards.
Go out without ever drawing a card.
Successfully bluff on a Wild Draw Four twice in the same game.
Go out with a Wild or Wild Draw Four card.
Successfully call UNO! and win the game.
Change the color of the discard pile 5 or more times in a single round.