Complete each achievement to get the allotted gamerscore.

Unlockable                 How to unlock
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815 (20)                  - Discover all the memories in Flashback 1	
Behind the glass (20)     - Discover all the memories in Flashback 3	
Sweet memory (20)         - Discover all the memories in Flashback 2	
Crash survivor (25)       - Complete Episode 1	
Locate the cockpit (25)   - Complete Episode 2	
Identity crisis (30)      - Discover all the memories in Flashback 4	
Persephone (30)           - Discover all the memories in Flashback 5	
Whatever it takes (30)    - Discover all the memories in Flashback 6	
Via Domus (50)            - Complete Episode 3	
Into the hatch (75)       - Complete Episode 4	
Behind the wall (100)     - Complete Episode 5	
Through the Flame (125)   - Complete Episode 6	
The way home (200)        - Finish the game	
A Turn of the Screw (10)  - Photograph A Turn of the Screw	
Boom boom (10)            - Open the secret door	
Castaways' Treasures (10) - Photograph: 1=Kate's plane 2=Charlie's guitar 
                            3=Locke's wheelchair