10 reasons games disappear from Steam
Did you buy Prey on Steam? I don't mean the 2017 version from Arkane and Bethedsa, I mean the 2006 version from Human Head Studios and 2K Games. If you didn't and want to now, you can't—the original Prey was quietly removed from Steam a few years ago. If you own it, you should still be able to play it, and if you can find a physical copy you may even be able to register the CD code with Steam. But you can't buy it on Steam anymore.