In order to promote the Linux release of the game, Hemisphere Games offered a free copy of Osmos to whoever wrote about the game on their blog. One of the recipients was Maxim Bardin of Linux Gaming News, who had already purchased a copy of the game. As such, he gave his free copy away as a prize in the first LGN Contest.
In the documentation, developer Eddy Boxerman explains how he came up with the concept:
The initial idea for the game came from a course I took on spacecraft dynamics, coupled with a Desbrun/Cani paper on deformable modeling using implicit surfaces. [geek.] I thought it'd be fun to control some simulated blobby thing, perhaps in a game. Then one day I realized I could prototype some interesting gameplay with simple circles and mass propulsion. With that prototype in hand, I realized there was deep and elegantly-balanced gameplay to explore here.