Ao Oni

Ao Oni is a role-playing horror video game, that was developed and published by noprops. It started off under the name Ao Oni 1.0, and then three sequels (which are named versions) include 3.0, 5.2, and 6.23 which all feature differently designed mansions and puzzles.

Bad Qualities

 * 1) All the characters are very surface level and aren't given much characterization besides their basic traits.
 * 2) Most of the time you do the same thing over and over, solve a puzzle, survive a chase, solve a puzzle, survive a chase.
 * 3) There's no real enemy variety (aside from the Blockman Oni in version 6) as the other three students turn into Oni after dying but they're just the same Oni with the only difference is having hair because they're supposed to be the characters who have turned into Onis.
 * 4) *The game at one point does show different kinds of Oni in a room, but you only see them once and then never again.
 * 5) The soundtrack is nothing more than one track that loops every 15 seconds when being chased.
 * 6) Many of the puzzles in the game are very confusing and requires checking everything and using everything on everything else.
 * 7) * Version 5 in particular suffers from this due to the Cipher Puzzle. It requires knowledge of a Japanese abacus (a Soroban) and how to count using it. The English and German translator actually left a note saying they're stumped on how to translate it better for western players, and that looking it up is really the only option.

Good Qualities

 * 1) Very well thought out puzzles, even more so in the older versions of the game.
 * 2) There are some good scares.
 * 3) * The cutscene when you're trapped in the jail could count.
 * 4) * Some puzzles take you to a different screen to solve them. During one such instance, you'll make two moves in the puzzle before it freezes... and the monster is suddenly walking straight towards the screen. And yes, he's right behind you when you return to the normal map.
 * 5) The Oni designs are pretty creepy as they fall into the uncanny valley since the faces have large eyes and such slender bodies.
 * 6) Decent graphics.
 * 7) The atmosphere is genuinely creepy since there's nothing more than silence which makes it all the more intense.

Reception
The independently developed freeware game gained a cult status online in Japan, gaining notoriety on websites such as Niconico and YouTube where Ao Oni-related videos exceeded 50 million views in 2013. The popularity of the game revolves around the effectiveness of its horror aspects despite being a simple game, with the background music often being cited as a key contributor to the chilling atmosphere used to incite fear.

Trivia

 * Ao Oni's design has an uncanny resemblance to Alexander Stuart Mahan, the developer of Yandere Simulator.
 * If the player names themself SOUTHPARK on the name screen, it will change the story to be more South Park-oriented and having the characters look as they would in South Park.
 * Most encounters with the monster involve running away while a hidden timer counts down. Entering TIMER as Hiroshi's name enables the player to see this clock.