Footage of Arkane's Half-Life spin-off, Ravenholm, has been posted online by Noclip, the YouTube channel known for producing some really great documentaries on games.
In the hour-long footage, you are shown the build Arkane created to show the current progress of the game to Valve. This means what you see is not a finished title, but it still offers a glimpse at what might have been.
In the game, you would have played as Lieutenant Shephard from Opposing Force, and met up with a fellow by the name of Father Gregory who took refuge in an asylum that acted as an experimentation center. The building at one time in its life featured a children's hospital, so you would have found toys on the floor of the place, making it "a bit creepy."
Ravenholm was a standalone spin-off of the Half-Life games, and it’s a shame it never saw the light of day.