Yup! My mom just had no idea that games could be that scary/inappropriate. It usually didn't have much of an effect on me but I did play two games as a child that I really shouldn't have: Resident Evil 2 and Nightmare Creatures 2, both on the PS1.
Now, I'm sure most here are familiar with RE2. The scariest scene for me is when Martin becomes a zombie with the close up and everything? I was terrified!
NC2 is a pretty bad game but one thing it does get right is that it has an extremely dark tone that is one of the creepiest in gaming, at least that I've ever played. From the monster designs, to the soundtrack and even the disfigured protagonist. I was way above my league when I played that, though I did get over my fears of the game by beating it using cheats haha.