Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
A very good year ( 20 points )	Collect 17 crystals in the game.
It's the journey that counts ( 15 points )	Successfully complete "Horn of Plenty" either alone or with a friend.
The UnderGardener ( 15 points )	Successfully complete "The Sum of all Things", either alone or with a friend.