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

Galactic Pilot (5 points): Beat Levels 1 and 2 in Arcade Adventure mode.
Crystal Power (10 points): Collect 500 Crystals in Arcade Adventure mode.
Secret Explorer (15 points): Beat 3 secret levels in Arcade Adventure mode.
Marauder Destroyer (15 points): In Split Screen Score Attack mode, cooperatively destroy 100 Marauders total.
Data Preservationist (20 points): In Arcade Adventure mode, collect 7 or more Data-Cores dropped by special enemies.
Raider (15 points): In Arcade Adventure mode, destroy all Factories found in the Toxic Sector.
Cosmic Scourge (25 points): Awarded for your 1,000th frag in ranked Death Match.
Sonic Speed (20 points): Beat Arcade Adventure, starting from Training, in 1 hour and 20 minutes or less.
Galaxy Crusher (25 points): Crush Arcade Adventure mode with 100% Crystals bonus on all levels including all Secret levels.
Score the Core (25 points): Collect all crystals in Single Player Score Attack to reach the secret ending level.
Destroyer of All (15 points): In Arcade Adventure mode, get the 100% Destructible clear bonus on 4 levels.
Maximum Overdrive (10 points): Achieve Maximum Overdrive in Arcade Adventure or Single Player Score Attack modes.