The latest superhero film to open this summer is off to a promising start. Captain America's $4 million haul compares favorably to the midnight openings of Thor ($3.3 million), X-Men: First Class ($3.37 million) and Green Lantern $3.35 million.

Critics have generally been kind to Captain America. Boxoffice.com's Todd Gilchrist wrote in his four-star review that, "To call Captain America: The First Avenger the best superhero movie of the year is absolutely true, but that's less of a compliment than it sounds."