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

Cartographer (5 points): Create and save a custom map.
Plunder (10 points): Capture a town.
Bombs Away (10 points): Destroy a neutral or enemy town's defense with a bomb.
Flushed Away (15 points): Use a whirlpool curse to teleport an enemy that is attacking your town.
Cherry Picker (15 points): Capture a neutral town after the enemy has destroyed its defenses.
Boom Boom (15 points): Sink two enemy ships with a single bomb.
Landlubber (15 points): Beat all easy challenges.
On the Account (25 points): Beat all medium challenges.
Freebooter (40 points): Beat all hard challenges.
King's Pardon (10 points): Beat every challenge in the game.
Sea Legs (10 points): Win a game in Player Match.
Old Salt (30 points): Win 10 games in Player Match.