[...] the prospect that Ant-Man, the miniscule Mighty Mouse of Marvel's stable of powerhouses, might join the brawny big-screen ranks of the Hulk, Thor and the rest has long held some pleasing irony. [...] that enticement — Oh, if it was something different! — went out the helicarrier window when, just weeks before shooting was to commence, Edgar Wright, the British blender of genre and comedy who had worked on the project for eight years, departed over "creative differences" — a sacrifice, seemingly, to the Marvel colossus. The precise source of the dispute is unknown, but it's clear enough from the final product, pushed forward with the quick insertion of director Peyton Reed (Bring it On, ''The Break-Up) and a rewrite by Adam McKay and others, that Ant-Man became bedeviled with staying true to its more modest size and idiosyncratic nature, and with the larger, blander demands of being a Marvel movie complete with superhero cameos and (optimistic) sequel set-ups. Lang is trying to right himself for the sake of his young daughter, Cassie (Abby Ryder Forston), and for paying child support to his ex-wife (Judy Greer, an actress too good to be twice relegated to the domestic sidelines in this summer's blockbusters). [...] as a parent might say, it's just a phase. Because you have to squint pretty hard to spot the differences from Marvel movie to Marvel movie.