Through historical investigation of the town and her husband's family, the protagonist uncovers a conspiracy to perform a ritual that will summon a Great Old One and put the planet in jeopardy.

Anchorhead was hailed by critics and players as one of the best interactive fiction games available due to its complex and intricate backstory and well-written dialogue and descriptions.

[2][3] The game is played through the perspective of an unnamed woman whose husband, Michael, suddenly inherits a large mansion in Anchorhead, Massachusetts, from family that he wasn't aware existed.

Croesus is attempting to summon a Great Old One named Ialdabaoloth, who takes the corporeal form of a multi-tentacled comet and is heading towards Earth at alarming rate.

[4] The game heavily draws elements from Lovecraftian literature, specifically The Dunwich Horror, The Music of Erich Zann, and The Festival,[1] as well as direct references, such as the Miskatonic River[5] and the city of Arkham.

Gentry also stated that some technological limitations encountered in Inform 6 would be addressed and NPC characters would be more interactive, thanks to the language's relatively easy declaration of relationships between the game objects.

Kulczycki praised the "excellent" writing, which had a "refreshing attention to detail," feeling that playing Anchorhead was "like reading a good book;" and the puzzles, although not particularly difficult, helped "build a richer environment for the player."

"[9] Terrence Bosky also called Anchorhead "a well-written, wonderfully designed adventure game," stating that it "works brilliantly as a Lovecraft pastiche, never entering the realm of parody."