Open Syobon Action (オープンしょぼんのアクション)

Open Syobon Action (オープンしょぼんのアクション) is a Linux game based on an unforgiving Japanese platformer. It is an open-source, cross-platform port built with SDL. The title is also known as Shobon no Action, Neko Mario, Cat Mario, and Cat MeOUCHio. Its game text is entirely in Japanese, but the controls and gameplay can be used without understanding the language.

The keyboard controls use Left and Right for movement and Z or Up for jumping. Space activates double-speed movement, while 0 during a game triggers self-destruction. Escape exits the game, F1 returns to the title screen, and keys 1 through 9 at the title screen select levels. The title screen also assigns 0 to Mystery Dungeon, where bugs may occur. The -nosound command-line argument disables sound.

The software is intended for Linux users looking for a deliberately difficult platform game, as well as players who want to introduce its demanding play style to someone unfamiliar with it. The supplied notes warn that playing may cause stress and state that people under 12 years old should not play. These warnings are part of the context for a game built around unexpected hazards and repeated failure.

Open Syobon Action is listed in MirrorNest under the multimedia category as an SDL-based interactive title for Linux. MirrorNest links directly to the official release rather than hosting a mirrored copy. Its license is unknown, so the catalog does not establish additional reuse or redistribution permissions. Bug reports can be sent to the listed snap issue tracker, and that snap is maintained by the Snapcrafters community rather than officially by the upstream developers. Anyone distributing the game to a large audience is asked to credit the original developer, Chiku (ちく).