Wild Talents Axes Of Design
These are Ken Hite's axes of design for superhero settings, taken from Wild Talents.
Everything here is used without permission.
These will help set parameters for your world; they can clarify the issues before you decide on something that you won't wind up actually enjoying or using. You can raise or lower any of these parameters independently of each other; raising all four of them together, by happy chance, replicates the traditional "Silver Age" feel of, well, four-color superhero comic books.