Accomplish the indicated achievement to get the corresponding 
number of Gamerscore points:

Empire Level 1 (5 points): Complete Level 1 on any difficulty
Empire World 1 (10 points): Complete World 1 on any difficulty
Empire World 2 (10 points): Complete World 2 on any difficulty
Empire World 3 (15 points): Complete World 3 on any difficulty
Empire World 4 (20 points): Complete World 4 on any difficulty
2x Multiplier (5 points): Get the multiplier to x2 in Single Player
10x Multiplier (25 points): Get the multiplier to x10 in Single Player