I believe the game was launched on Dec 11 2009, at the same time as the other flash game. Notably, each time you investigate an item it adds a log to the 'notes section', which quickly becomes somewhat of a wiki itself. There is a wealth of information in there for the site. I have also made a local back-up of the opening (CG) cutscene.
The general principle is that you are controlling a ROVR on the planet surface, deployed by the Venture Star for some early exploration. Among the interesting new revelations is the name of one of the predecessors of the Venture Star, the ISV Bradbury that deployed the first two ROVR units.
Me being the obssessive fan i am, i took the liberty of scanning every object in the entire game, and screenshotting the entire in-game wiki...
and all of the actually useful images...
Reviews and some behind the scenes information- http://venturebeat.com/2009/12/17/multiverses-remix-makes-it-easy-to-create-avatar-spinoff-games/
Edit: looks like that site also hosts a backup of the original page around the game- the game is set 70 years before the film, when Pandora was first investigated... which contradicts our discovery date of 2129, although I can't find our citation.  Not the first thing that contradicts 2129; the Iphone game did too. Anyone have the activist survival guide to check? I would actually advocate removing that 2129 date unless someone can find a citation for it; its not on pandorapedia either.
Edit edit: Found some rough dates in the PC games' encyclopedia, that points to a Pandora discovery date "in the late 21st century". Judging by the ROVR thing and the game's pandorapedia we can now place the discovery of Pandora between 2050 and 2077. From what I can gather, the old 2129 figure was simply based on a propaganda poster that celebrated 25 years of development by the RDA; that hardly indicates "discovery'. I have updated the timeline.