Go to multiplayer in the menu, and select Xbox LIVE. It doesn't matter how high you get ranked.

Play single player campaign mode and reach level 10. Defeat Blockbeard to unlock this achievement.

Destroy a total of 1.000.000 blocks. All blocks you destroyed from all levels are counted.

In any level, online or offline, kill 20 enemies within one minute to unlock this achievement.

Kill a total of 50 enemies with a longshot. All longshots through the entire game are counted.

Use all 20 power-ups in the game, including the red power-downs. The tutorial level doesn't count.

Play through all 80 single player levels successfully to unlock this achievement.

Shoot 50 zombies, 50 robots, 50 pirates and 50 soldiers. All levels online and offline count.

Kill 5000 enemies throughout the game to unlock this achievements.

Kill all different types of enemies in Rocket Riot to unlock this achievement.

Play endurance or co-op with friends, and beat level 50 to unlock this achievement.

Kill 3 enemies with one shot.