Complete the following achievements to unlock Xbox Live Gamerscore points.
| Achievement | How to unlock |
| 4 8 15 16 23 42 (15 points) | Photograph numbers on sealed hatch
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| 815 (20 points) | Discover all the memories in Flashback 1
|
| A Turn of the Screw (10 points) | Photograph A Turn of the Screw
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| Beam of light (20 points) | Photograph beam of light coming from the hatch
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| Behind the wall (100 points) | Complete Episode 5
|
| Behind the glass (20 points) | Discover all the memories in Flashback 3
|
| Blackmailer (15 points) | Convince Locke to help
|
| Boom boom (10 points) | Open the secret door
|
| Button pusher (15 points) | Enter the numbers
|
| Castaways' Treasures (10 points) | Photograph: 1- Kate's plane 2- Charlie's guitar 3- Locke's wheelchair
|
| Crash survivor (25 points) | Complete Episode 1
|
| Desmond's Past (10 points) | Photograph: Kelvin's jump suit Medical cabinet with vaccines Desmond's mural
|
| Dharma Ride (15 points) | Photograph Dharma van
|
| Hero's hero (25 points) | Save Jack
|
| Identity crisis (30 points) | Discover all the memories in Flashback 4
|
| Into the hatch (75 points) | Complete Episode 4
|
| Locate the cockpit (25 points) | Complete Episode 2
|
| Mapping the Island (10 points) | Photograph: 1- Blast door map 2- Blast door map for the hidden entrance 3- Sayid's cable map
|
| Pearl Station (20 points) | Photograph Pearl Station emblem
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| Persephone (30 points) | Discover all the memories in Flashback 5
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| Radzinsky (15 points) | Photograph bloodstain on the Swan ceiling
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| Save the castaways (15 points) | Prevent the fuel leak from igniting
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| Showdown (10 points) | Successfully confront Beady Eyes
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| Slave (15 points) | Photograph skeleton in Black Rock
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| Staff Station (20 points) | Photograph Staff Station emblem
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| Sweet memory (20 points) | Discover all the memories in Flashback 2
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| The way home (200 points) | Finish the game
|
| Through the Flame (125 points) | Complete Episode 6
|
| Via Domus (50 points) | Complete Episode 3
|
| Whatever it takes (30 points) | Discover all the memories in Flashback 6
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