Is it a documentary? Yes I suppose, but it's hardly indepth and comes across more of a breakdown of what has happened so far in regards to movie/short and television releases.
Regarding the actual background, casting and creation it's very thin on the ground and that's a damn shame because it's logically what you'd have expected going into this thing.
Short stubby interviews, a couple of insights but mostly stock footage from Iron Man through to the first Guardians Of The Galaxy.
A real let down.
Not enough actual content
Hardly a documentary
Things I Learnt From This Documentary:
Even Jackson admits he was an oddd casting choice for Nick Fury
Agent Coulson is glue