I thought this was interesting, but under "Clive Barker's Undying," or simply "Undying," there is no such game available on Steam, nor is there a Steam forum for it. There are many games available here that are not available on Steam, interestingly enough.

I'm working with Undying right now as an old game, which is why this came up. A few years ago I checked to see how many games were available here and on Steam, as sometimes I buy more than one copy if there's a sale, etc. I was surprised to see several of the games I own are not available on Steam. As far as older games go--GOG is much superior to Steam, imo. in game availability and in configuring old games to run on modern hardware and OSes.