who developed it?
Blendo Games.
Gravity Bone
 developed and published by Blendo Games.
what is gravity bone? A freeware adventure game
wiki:25550785
Gravity Bone [SEP] Introduction
Gravity Bone is a 2008 freeware adventure game developed and published by Blendo Games. The game employs a modified version of id Software's id Tech 2 engine—originally used for "Quake 2"—and incorporates music from films by director Wong Kar-wai, which were originally performed by Xavier Cugat. Four incarnations of the game were produced during its one-year development; the first featured more common first-person shooter elements than the released version. Subsequent versions shifted in a new direction, with the inclusion of more spy-oriented gameplay. The game was released for Microsoft Windows in August 2008. "Gravity Bone" received critical acclaim from video game journalists.