Games like Unseen Diplomacy
Games like Unseen Diplomacy include Thief Simulator, Five Nights at Freddy's: Secret of the Mimic, Crime Scene Cleaner, Green Hell VR, and BONEWORKS. We matched them by the tags players give Unseen Diplomacy on Steam (Action, Simulation, Indie, Adventure, and Action-Adventure): closest matches first, and among equally close ones the better-known games.

Thief Simulator
Shared: Simulation · Action · Adventure

Five Nights at Freddy's: Secret of the Mimic
Shared: Action · Adventure · VR

Crime Scene Cleaner
Shared: Simulation · Action · First-Person

Green Hell VR
Shared: Action · VR · Simulation

BONEWORKS
Shared: Action · VR · Adventure

Rise of the Tomb Raider™
Shared: Action · Adventure · Exploration

Thief Simulator 2
Shared: Simulation · Action · Adventure

Hard Bullet
Shared: Action · VR · Simulation

A Plague Tale: Requiem
Shared: Action · Adventure · Action-Adventure

Contraband Police
Shared: Simulation · Action · First-Person

Tomb Raider Game of the Year
Shared: Action · Adventure · Exploration

Drug Dealer Simulator
Shared: Simulation · Action · Indie

Microsoft Flight Simulator X: Steam Edition
Shared: Simulation · Adventure · Realistic

Deliver Us The Moon
Shared: Action · Indie · Adventure

Steep™
Shared: Action · Simulation · Exploration

BONELAB
Shared: VR · Action · Action-Adventure

X-Plane 11
Shared: Simulation · VR · Realistic

The Forest
Shared: Adventure · Action · First-Person

SnowRunner
Shared: Simulation · Adventure · Exploration

Internet Cafe Simulator 2
Shared: Simulation · Exploration · First-Person

The Long Dark
Shared: Exploration · Adventure · Simulation

IRON NEST: Heavy Turret Simulator
Shared: Simulation · Indie · Action

PEAK
Shared: Adventure · Exploration · First-Person

Elite Dangerous
Shared: Simulation · Exploration · VR