It's a free game that you can download from the developer's site but only for PC. Unfortunately there is no native Mac version, so here is a Wine edition. Have fun!

Gravity Bone is a first person adventure in which the main character, Citizen Abel, supposed to be a spy is sent out on two different missions. The first mission is a short tutorial level that teaches you the basics of movement and navigation for the game. The second level seems to continue the tutorial trend. You learn new skills like using items. You have another relatively simple objective that seems routine enough to complete. It is set in the fictional city of Nuevos Aires.

IGN gave a very positive impression of the title, commenting that it is "a first-person adventure with simple gameplay, but the cohesiveness of its striking visual presentation, soundtrack and effects, and almost entirely incomprehensible story combine to create an atmosphere of peculiar strength." The game was awarded the GameTunnel Best Arthouse Game 2008 award.