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

  Complete The Game (25 points): Rescue Alissa and complete the game. 
  Choice is Good (25 points): Receive both endings. 
  Points III (25 points): Score 50,000 points. 
  3rd Grade (15 points): Use a paper airplane. 
  Points II (15 points): Score 30,000 points. 
  Accelerate Your Hero (25 points): Complete Episode 3. 
  Buddha Says (15 points): Complete Episode 2. 
  Unknown Territory (15 points): Finish the first page. 
  Points I (10 points): Score 10,000 points. 
  Orange Bull (10 points): Use the Iced Tea to restore your health. 
  Boo-Ya! (10 points): Use the dynamite. 
  Rats! (10 points): Rescue and pick up Roadkill.