I think the biggiest feat from Guradian of the Galaxy's success was this shows that you can make a movie without a origin and pretty much jump straight in to it. The execution was well done, yes many would want more from the film and a better villian so to speak. But think about how it didn't fall flat without knowing what to expect from this film. I think if anything the second one will improve what it dropped in some areas of the film. "MCU for Life!"