Full list of all 12 Carcassonne achievements worth 200 gamerscore. It takes around 8-10 hours to unlock all of the achievements on Xbox 360.
Scored a total of 5000+ points from all your Carcassonne games combined
Scored a City with 9+ tiles in a Player Match vs. 2 or more opponents
Scored 150+ points in a Single Player game
Won a Player Match against 3 or more opponents
Scored a total of 2000+ points from all your Carcassonne games combined
Won 1 Ranked game
Defeated an opponent in a Player Match by 50+ points
Scored 2 adjacent Monasteries in Single Player
Scored 50+ points in Single Player
Scored a Farm supplying 4+ Cities in Single Player
Scored a City with 3+ tiles in Single Player
Scored a road with 5+ tiles in Single Player