Games like Gnosis
Games like Gnosis include Gorogoa, Storyteller, THE LONGING, Sally Face - Episode One, and Machinarium. We matched them by the tags players give Gnosis on Steam (Interactive Fiction, Point & Click, Gothic, Choose Your Own Adventure, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Gorogoa
Shared: Hand-drawn · Point & Click · Atmospheric

Storyteller
Shared: Point & Click · Interactive Fiction · Hand-drawn

THE LONGING
Shared: Point & Click · Choose Your Own Adventure · Atmospheric

Sally Face - Episode One
Shared: Point & Click · Atmospheric · Mystery

Machinarium
Shared: Point & Click · Hand-drawn · Atmospheric

Suzerain
Shared: Choose Your Own Adventure · Interactive Fiction · Point & Click

The Henry Stickmin Collection
Shared: Choose Your Own Adventure · Point & Click · Hand-drawn

Pentiment
Shared: Interactive Fiction · Hand-drawn · Choose Your Own Adventure

The Room
Shared: Point & Click · Atmospheric · Mystery

Unforeseen Incidents
Shared: Point & Click · Interactive Fiction · Atmospheric

The Case of the Golden Idol
Shared: Point & Click · Mystery · Interactive Fiction

Your Turn To Die -Death Game By Majority-
Shared: Point & Click · Interactive Fiction · Choose Your Own Adventure

The Room Two
Shared: Point & Click · Atmospheric · Mystery

Insomnia: Theater in the Head
Shared: Point & Click · Hand-drawn · Atmospheric

NORCO
Shared: Point & Click · Atmospheric · Mystery

Rusty Lake Paradise
Shared: Point & Click · Atmospheric · Mystery

Strange Horticulture
Shared: Point & Click · Mystery · Atmospheric

The Room Three
Shared: Point & Click · Mystery · Atmospheric

Cube Escape Collection
Shared: Point & Click · Mystery · Atmospheric

Dagon: by H. P. Lovecraft
Shared: Atmospheric · Interactive Fiction · Point & Click

Firework
Shared: Atmospheric · Mystery · Indie

Kathy Rain 2: Soothsayer
Shared: Point & Click · Atmospheric · Mystery

The Roottrees are Dead
Shared: Point & Click · Mystery · Atmospheric

The Tiny Bang Story
Shared: Point & Click · Hand-drawn · Atmospheric