Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock
A perfectionist (100 points)	Collect 60 stars.
First blood (50 points)	Die for the very first time.
Getting started (100 points)	Collect 20 stars.
In my army now (50 points)	Turn 10 soldiers into zombies.
No leader is perfect (50 points)	Lose a zombie.
Non omnis moriar (50 points)	Turn a human into zombie.
Playing well (100 points)	Collect 40 stars.
Snowrunner (100 points)	Beat all winter levels with total time lower than 8 minutes.
Speedrunner (100 points)	Beat all summer levels with total time lower than 15 minutes.
Summertime (100 points)	Finish all summer levels.
Ultimate zombie leader (100 points)	Collect 90 stars.
Winter has come (100 points)	Finish all winter levels.