Construction

Construction (コンストラクション) is a video game editor developed by Toshio Fujita. Despite its origins, command options are displayed in English. A sequel called Construction Contest was released six months later.

Gameplay
While the game itself is nothing more than a Pac-Man clone at first glance, its real draw is the ability to edit maze layouts, sound effects, and character graphics via command inputs. Tweaking the game's speed is also an option. Players can save their creations and load them for others to try.