“Birdman,” starring Michael Keaton, has got to be the best offbeat superhero movie since “Paper Man,” starring Ryan Reynolds, as Captain Excellent, in 2009. You can also include “Super,” starring Rainn Wilson, Ellen Page, and Liv Tyler. Hmm, then there’s “Kick-Ass” (2010) and “Kick-Ass 2” (2013). We could maybe add a few more. They emerge at a nice steady pace.
