"crayon physics", the original prototype of this game, is purho's tenth "rapid-prototype project" inspired by the rules of the experimental gameplay project, and was developed in five days using resources freely available under a creative commons license. the game was first released for android and developed by acrodea korea, inc. on june 10, 2007, purho announced that he would be developing a level editor to permit user-created levels, although by june 15 fans of the game had already worked out the level format and had released new levels for the game. the level editor was released on june 30. "crayon physics" was built with simple directmedia layer middle-layer and released as freeware.