There is an under development adventure game that I would like to mention, because I was pretty much intrigued by its atmosphere and because some of the users of this forum like games inspired by Lovecraft.
Saint Kotar
Description
Saint Kotar is a 2.5D point and click adventure game in development for Windows, Mac, and Linux. The game merges psychological horror narrative and classically inspired point 'n click adventure mechanics with switchable characters.
Digitally hand-painted with a distinctive art style that fits the game’s mood, fully voiced and featuring an original eerie soundtrack, Saint Kotar draws inspiration from p&c classics like Broken Sword and Monkey Island, along with the works from horror fiction writers such as H.P. Lovecraft and Edgar Allan Poe.
The plot
Invited to attend an exhibition of rare medieval art, the protagonists travel to Saint Kotar at the end of October 2006. The welcoming is cold, as they find themselves dragged abruptly into a macabre series of murders, allegedly related to Satanic worship and witchcraft. These dreadful acts compel the protagonists to follow the shadow of something deeply hidden behind the town’s dark past.
Notes
I have discovered the game thanks to this thread on AdventureGamers and since then I have been followed its development.
For example, here you have a video that compares their old 2D mode with the new 2.5D mode, explaining why the developers finally have chosen the 2.5D solution (a la Grim Fandango):
Links
Official website, concept art and first images
Development blog