Ohr Oni is a single-player role-playing game in which players explore underground tunnels, solve puzzles, and uncover the story behind a mysterious blue monster and a recent earthquake. In this game, a Japanese schoolboy is trapped in underground tunnels after a train derailment caused by a strange earthquake, surrounded by dead bodies and haunted by rumors of a big blue Oni. It stands out with its nostalgic 8-bit aesthetic inspired by late-80s Famicom games, its short gameplay experience that can be completed in under 15 minutes on a second playthrough, and its two different endings, offering a compact yet engaging horror adventure.