Games like Eternal Affairs
Games like Eternal Affairs include Roadwarden, The Life and Suffering of Sir Brante, Suzerain, DevilConnection, and Dark Messiah of Might & Magic. We matched them by the tags players give Eternal Affairs on Steam (RPG, Interactive Fiction, Choose Your Own Adventure, First-Person, and Text-Based): closest matches first, and among equally close ones the better-known games.

Roadwarden
Shared: RPG · Text-Based · Interactive Fiction

The Life and Suffering of Sir Brante
Shared: RPG · Interactive Fiction · Choose Your Own Adventure

Suzerain
Shared: Choose Your Own Adventure · Interactive Fiction · RPG

DevilConnection
Shared: Choose Your Own Adventure · Interactive Fiction · Dark Fantasy

Dark Messiah of Might & Magic
Shared: RPG · First-Person · Dark Fantasy

The Life and Suffering of Sir Brante — Chapter 1&2
Shared: Interactive Fiction · Choose Your Own Adventure · RPG

Choice of Robots
Shared: Choose Your Own Adventure · Interactive Fiction · Text-Based

Love Is All Around
Shared: First-Person · Interactive Fiction · RPG

Tainted Grail: The Fall of Avalon
Shared: RPG · First-Person · Dark Fantasy

Aliya: Timelink
Shared: RPG · Interactive Fiction · Text-Based

To the Moon
Shared: Interactive Fiction · RPG · Emotional

Breakout 13
Shared: Interactive Fiction · Choose Your Own Adventure · RPG

Sorcery! Parts 1 and 2
Shared: RPG · Choose Your Own Adventure · Interactive Fiction

Fatekeeper
Shared: RPG · First-Person · Dark Fantasy

The Elder Scrolls IV: Oblivion® Game of the Year Edition (2009)
Shared: RPG · First-Person · Fantasy

Love is All Around: Echoes of Yesterday
Shared: RPG · Interactive Fiction · Choose Your Own Adventure

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Fantasy · Dark Fantasy

Billionaire Lovers
Shared: RPG · Interactive Fiction · First-Person

Lost Wiki: Kozlovka
Shared: Interactive Fiction · Conspiracy · Detective

Wayhaven Chronicles: Book One
Shared: RPG · Choose Your Own Adventure · Interactive Fiction

Avowed
Shared: RPG · First-Person · Fantasy

ELDEN RING
Shared: RPG · Dark Fantasy · Fantasy

Clair Obscur: Expedition 33
Shared: RPG · Fantasy · Dark Fantasy

DARK SOULS™: REMASTERED
Shared: RPG · Dark Fantasy · Fantasy