Achieve the corresponding Code Geass-related goals (and Zero Point) by performing the corresponding tasks. Note: If you have at least 5 Zero Points at the end of Stage 37, Roger and Banjou will save Shirley from being killed by Rolo. After Stage 49, you will have the option to trust or distrust Zero. Choose "Trust Zero" (bottom option) to access a secret route for the good ending to the Code Geass storyline:
GOAL - HOW TO UNLOCK Zero Point #1 - In the first prologue stage, defeat Cornelia with Zero piloting Gawain. Zero Point #2 - Complete Stage 7 (Kallen to Kummen Route). Zero Point #3 - Complete Stage 14 (Kallen Route) Zero Point #4 - In Stage 17, defeat Da Longdan with Zero piloting Shinkiro. Zero Point #5 - In Stage 27, defeat Wufei before reinforcements arrive. Note: This will prevent Zero Points 6 and 7 from being unlockable. Zero Points #6 and #7 - In Stage 27, reduce Heero's HP by half before reinforcements arrive. Note: This will prevent Zero Point 5 from being unlockable. Zero Point #8 - Zero has a kill count of at least 70 before the end of Stage 37.