Single-player games like Project Unknown
Below are 11 single-player Steam games similar to Project Unknown, 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 Project Unknown page.
Ranked picks
- 1
Deepscape Inc
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
A 2 to 4 player co-op horror game. You wake up marked with an ID number you can't see on your own back. Only your fellow inmates can read it. Find each other, share your numbers, reach your validation rooms, and get out before whatever roams the halls finds you first.
- 2
Dark Past
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Dark Past is based on psychological horror by paranormal activity occurring during your investigations. Play solo or up to 4 players to try and solve the mystery of what entity is left behind.
- 3
Phasmophobia
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Phasmophobia is a 4 player online co-op psychological horror. Paranormal activity is on the rise and it’s up to you and your team to use all the ghost-hunting equipment at your disposal in order to gather as much evidence as you can.
- 4
The Backrooms - Nightmare Dimension
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
The Backrooms - Nightmare Dimension is a Co-op online horror game with up to 4 players, where you and your friends take on the roles of soldiers who are part of the SCP Foundation with the mission to eliminate the mysterious entities found in the infamous place called "the Backrooms".
- 5
Grinnel
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
If you stop, the light dies. If you turn, darkness takes over. As a patient trapped in Grinnel, escape this psychological horror nightmare with Dr. Esin. Use your visor in the atmospheric labyrinth and never look back; in this surreal thriller, your gaze is your worst enemy.
- 6
Moved mind
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Moved mind is a first person narrative psychological horror game, where you will be the subject of a psychological experiment where you will have to face your fears and differentiate reality from the symptoms of your illness.
- 7
Gluua
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Indie with Project Unknown.
first-person 1-4 multiplayer horror game. The game will allow players to take on the role of a spirit liberator who will be able to freely choose missions based on the difficulty and readiness they like or want to do. Players will encounter the supernatural and find the truth in that place.
- 8
Mantra
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Mantra is a multiplayer (1-4 player) and single-player psychological-horror game with high tension. Do whatever it takes to save your soul that has been possessed by an demonic spirit. If you don't, demon will imprison you in hell for eternity.
- 9
The Dark Pictures Anthology: Man of Medan
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Adventure with Project Unknown.
The Dark Pictures Anthology is a series of stand-alone, branching cinematic horror games that can also be played online with a friend. In Man of Medan, five friends set sail on a holiday diving trip that soon changes into something much more sinister.
- 10
Implements of Hell
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Implements of Hell is a first-person psychological horror game. Explore the mysteries, unlock the secrets, and change the outcome in a slow-paced atmospheric, and extremely horrifying experience.
- 11
Omitted
Single-player alternative to Project Unknown — playable solo, no multiplayer required. Shares Action and Indie with Project Unknown.
Omitted is a first-person psychological horror game. Experience being left alone in an old hospital, discover its secrets and try to survive.