Pocket Dungeons are system agnostic tabletop RPG adventures with themes of "you should not have gone there" and "you don't know what effect that might have" and "why did you eat that" running throughout. Low on combat, high on weird, easily added as one-offs or as standalone games.
The Corruption of Pelursk is the true horror adventure of this collection, as it's a randomized hexcrawl on a conscious, haunted island that is trying to destroy you.
The first pocket dungeon I ever wrote!
Ghost Houses is for sure the saddest one, but, in maybe a hopeful way? Legit there is, like, no combat necessary here. Just exploration and feelings.