Insmouse no Yakata

Innsmouth no Yakata is a first-person horror game set in 1922, where players take on the role of a private detective trying to escape a monster-infested mansion with an artifact known as the Necronomicon.

Each stage represents a floor of the mansion, and players must find a key to unlock an exit door within a set time limit that varies by level. The game uses a twin-stick control scheme: one stick for movement and the other for aiming and shooting. After completing a stage, players are presented with a stage select screen featuring branching paths similar to those in the Darius series. Based on their completion time, players will either advance to a higher floor (if they finish in under 30 seconds) or descend to a lower floor (if they finish within the last 30 seconds). The game concludes when the player successfully escapes after navigating one of the final floors.

Throughout the game, players face off against fish-like monsters that can either be shot or avoided. Ammunition and health pickups are scattered across the floors. A map screen displays the player's current location and gradually reveals the layout of each floor. Players can also find two types of collectible orbs: white orbs that uncover the entire map and black orbs that highlight item locations. The game features 45 different floors, though only 13 can be accessed in a single playthrough. There are four possible endings, including a "joke" ending that resets the player to the beginning of the game.