Eversion is a light, Mario-esque platformer. It has happy music, 8-bit graphics, and a unique game mechanic. It’s unfortunately only available for Windows (though it ran without error on my Mac via Crossover). At first, it seems like somebody’s cute attempt at 1980’s era platforming game play. But very quickly it becomes clear that the game has an agenda and it’s not all blue skies and happy flowers. I won’t ruin it for you, but give the game a shot. It gets pretty hard but I advise you to stick with it. Be sure to ignore the comments on the main download page, as they will spoil it for you.
Eversion works very much like Nanashi No Geemu in that it lulls you into a comfortable zone with a familiar style. It also twists its particular knife pretty slowly; it’s not until the fifth or sixth level that you really realize how carefully the entire thing has been planned. But the result is pretty neat, once again proving that horror does not require high-end graphics tech to be effective. (Interestingly, the game also adds more weight to the idea that sound plays a much more important role in the creation of tension.)
So, another ingredient of successful horror games: familiarity as a way to surprise the player. Not every title does this, but I think that a number of the really good ones do.