Single-player games like Unnatural Investigations
Below are 7 single-player Steam games similar to Unnatural Investigations, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Unnatural Investigations page.
Ranked picks
- 1
Entities
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action and Indie with Unnatural Investigations.
Dive into horror in Entities. Solo or up to 4-player matches offer dynamic puzzles, relentless entities, and extraction shooter mechanics. Investigate, unlock paths, and survive in dangerous zones as a private operator. Master skill and terror. Are you ready to confront the unknown?
- 2
Demonsomnia
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action with Unnatural Investigations.
Demonsomnia is a CO-OP multiplayer bodycam horror game focused on the impact of nuclear reactions. Radiation has spread everywhere, so put on your gas mask. Your goal is to activate the nuclear reactor device and escape without being caught by mutants.
- 3
Painkiller
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action with Unnatural Investigations.
The classic Painkiller series is back! Battle through Purgatory in fast-paced co-op action, wielding infernal weapons against relentless demonic hordes. Condemned for your sins, the Voice of the Creator offers you a chance at redemption. Will you seize it or be lost to darkness?
- 4
Left 4 Dead 2
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action with Unnatural Investigations.
Set in the zombie apocalypse, Left 4 Dead 2 is a co-operative action horror FPS takes you and your friends through the cities, swamps and cemeteries of the Deep South, from Savannah to New Orleans across five expansive campaigns.
- 5
Tom Clancy’s Rainbow Six® Extraction
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action with Unnatural Investigations.
Tom Clancy's Rainbow Six® Extraction is a tactical, co-op, PvE first-person shooter where you and your squad face an evolving alien threat. Teamwork, tactics, and flawless execution are key to your survival.
- 6
Unreal Tournament 3
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action with Unnatural Investigations.
Now includes the free Titan Pack expansion! The Titan Pack gives players a substantial amount of enhanced features and new content, including many original environments, new gametypes, the namesake Titan mutator, powerful deployables and weapons, new characters, and the Stealthbender.
- 7
Tannenberg
Single-player alternative to Unnatural Investigations — playable solo, no multiplayer required. Shares Action and Indie with Unnatural Investigations.
Experience authentic First World War action with 64 player battles of maneuver on the Eastern Front. Grab your rifle, ready your sabre and keep your gas mask close as you prepare to play a part in one of the most significant conflicts in history!