For all the world-building and king-making done here, Marvel’s Mayflower voyage into cinematic domination is really just a pretty good movie.  And much of that is due to the strength of Downey Jr., who makes the deadlifting of a movie star look easy.  Everything else about it is engaging and well-done enough, um—serviceable, that’s the word I’m looking for!   Serviceable.  If you’re looking to venture deeper into Marvel waters, you gotta start with this one.