Swedish independent developers Frictional Games (Penumbra series) have released a gameplay teaser of their next game, currently titled Unknown, along with three screenshots. Set in an 18th century castle the game will feature the same brand of suspense and physics based puzzles as the Penumbra series.
Here is a brief quote from the press release:
The video gives a quick demonstration of the mood and style we are aiming for, as well as demonstrating the maturity of the in-house developed HPL2 game engine. We have expanded the engine to include tools for testing, creating and editing levels - all of which have been used to create the level in the teaser. The tools are used during the production of the game and are also going to be part of the final release, allowing for end-user content creation. "Unknown" has recently entered full production and is preliminary scheduled for an early Q2 2010 release.