Full Gameplay Walkthrough...

Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock	Points
A new watcher	Prevent Cthulhu from awakening.	80
Addicted	Use ten doses of Lichen.	20
Against the tide	Cross the maze without reassembling the cursed totem.	40
Artist	Reconstruct Mei's drawing.	20
Augmented agent	Find all evolutions.	80
Better than Pandora	Open the door without letting the matter spill out.	40
Beyond the senses	Using sonar, reveal the invisible tentacles of the citadel's guardian.	40
Cosmic Abyss	Replace the watcher.	80
Cthulhu fhtagn	Translate the temple inscriptions.	20
Elementary	Solve fifteen deductions.	20
Full charge	Find all energy upgrades.	80
His master's voice	Reach the star without killing the guardian.	40
In deep waters	Restore the seal and destroy the deep one.	40
Inspector	Find ten sub-clues by inspecting objects.	20
Let there be light	Reactivate the PIT station.	20
Linguist	Translate the language of the great race of Yith.	40
Macro waves	Reveal twenty-five different clues using sonar frequencies.	20
Mens sana	Finish the game without exceeding the corruption threshold.	80
Open Sesame	Unlock a yith mechanism using sonar.	40
Thanks Key	Analyze twenty-five clues.	20
The Awakening	Find Mei in the Other World.	20
The Citadel	Get the Star of Shamash.	20
The Excavation	Cross the maze.	20
The Last door	Reach the prison.	20
The Other World	Leave the Other World.	20
The Temple	Escape from the deep one.	20
Where am I?	Teleport using the Star of Shamash.	40