Sanitarium is described as 'Originally released in 1998 on PC, and awarded as the Adventure Game of the Year, The timeless horror point-and-click, Sanitarium, is returning to frighten the bravest adventure game fans'. There are more than 25 games similar to Sanitarium for a variety of platforms, including Windows, Steam, Mac, Linux and Playstation. The best alternative is Thief. It's not free, so if you're looking for a free alternative, you could try SCP: Containment Breach or Cry of Fear. Other Sanitarium like games are Amnesia: The Dark Descent (Paid), Resident Evil (Paid), Silent Hill (Paid) and Slender: The Eight Pages (Paid).
Thief is a series of stealth video games in which the player takes the role of Garrett, a master thief in a fantasy/steampunk world resembling a cross between the Late Middle Ages and the Victorian era, with more advanced technologies interspersed. Represent entire series of Thief games.
Amnesia: The Dark Descent is a first person survival horror game for Windows, Mac OS X and Linux. The game features a protagonist named Daniel exploring a dark and foreboding castle, while avoiding monsters and other obstructions as well as solving puzzles.
Resident Evil, known as Biohazard in Japan, is a survival horror video game-based media franchise created by Shinji Mikami and Tokuro Fujiwara and owned by the video game company Capcom. Represent entire series of Resident Evil games.
Slender: The Eight Pages is a free indie-developed psychological horror/survival horror video game for Microsoft Windows and OS X. The game is based on the Something Awful forums' creation, Slender Man.
SCP: Containment Breach is an indie survival horror video game based on the stories of the SCP Foundation website. The player guides a test subject, D-9341, through many obstacles inside of a facility belonging to the shadowy SCP Foundation.
Layers of Fear is an foray into madness, a first-person horror game that sets a tone of fear and dread through provocative story telling as you explore a Victorian setting complete with mood-setting art pieces.