Here is the full list of all 12 Catan achievements worth 200 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox 360.
You invited someone to play Catan.
You beat three Hard AIs in Catan.
You won Largest Army 10 times.
You won Longest Road 10 times.
You collected 250 VP's.
You collected 100 VP's.
You collected 25 Victory Points.
You beat three Moderate AIs in Catan.
You acquired 100 resource cards.
You built a settlement in Catan.
Collect 500 Victory Points in ranked match play.
Collect 1000 Victory Points in ranked match play.