Although “Guardians” is a Marvel Comics property, it lacks the name recognition of staple heroes, like “Spider-Man,” “Iron Man” and “Captain America.” It also relegates its most marketable stars (Bradley Cooper and Vin Diesel) to roles where their faces are hidden. Ultimately, the perceived marketing issues don’t matter because the movie – a wild mix of comedy and science-fiction – is a blast, and theatrical audiences figured that out right away.