The video shows found footage of three friends who get stranded on a tropical island and caught in the game's plot.
The trailer, which was leaked earlier today, also revealed the game's release date for September 6. Ubisoft has confirmed the September 6 release date for Europe, and September 4 for North America.
Revealed at last year's Ubisoft E3 press conference, the sequel will return to the tropical setting made famous by the first Far Cry.
Far Cry 2, which was released in 2008, saw the open-world series move to Africa.
Far Cry 3 will be available on Xbox 360, PS3 and PC.
Watch the Far Cry 3 E3 gameplay demonstration below (adult content):