Cthulhu The Cosmic Abyss — Chapter 4

Placeholder — awaiting final game structure.

Step-by-step

How do I unlock Thanks Key?

Have KEY analyze 25 distinct clues. Chapters 1 and 2 of the demo contain more than half of them if you scan thoroughly.

Where is the quartz alloy?

Near the occult book pages on the shelves in May's house. Scan it on the Mineral sonar frequency when KEY unlocks that step.

I missed a clue — can I go back?

Most demo areas allow free backtracking inside the chapter. If a door locks, reload an earlier save if available.

Hardest achievement in the demo?

Thanks Key or full frequency coverage — both reward slow, methodical scanning.