Mark Ruffalo has confirmed that the upcoming "Avengers: Age of Ultron" will be a "darker" film than its predecessor.

"I would say that it's better, it's cooler, it's more awesomer," he said, according to Cinema Blend. "It's a little bit darker, but also really had Joss Whedon's incredibly witty and sly sense of humor."

The first "Avengers" movie was anything but dark. The film was filled with tremendous gags that pitted superheroes with completely different personalities against one another and then eventually united them to a common cause. The film's darkest moment came when Agent Coulson, played by Clark Gregg, gets "killed." In the context of the film, it is a pretty tragic moment, but in the larger scheme of the Marvel United (one in which "Agents of SHIELD" exists) it really is nothing more than a "fake" demise.

So how would this upcoming film be darker? One major difference that stands out is the choice of villain. In the first film, Loki, the brother of Thor, was the main antagonist. However, anyone that has watched the films and Tom Hiddleston's brilliant performance knows that he is more of a misguided anti-hero than a villain. Furthermore, the Avengers' final battle was against a bunch of generic aliens, taking away from the seriousness of the subject matter.

In the case of the sequel, director Joss Whedon is bringing in Ultron, a robot that has grown in intelligence and which has at times been depicted as genocidal. This alone makes the character far more nuanced and potentially more dangerous than anything the "Avengers" have ever faced.

The whole idea of "darker" superhero movies has been a trend for a few years now. Christopher Nolan's Batman trilogy centered on more philosophical themes as the nature of the hero while portraying Gotham as a more destructive and venomous locale. The recent reboot of "Man of Steel" also created a number of ponderous questions by subverting Superman's role as a beloved hero and turning him into a stranger trying to find his place in the world.

What will Whedon do with his second "Avengers" flick? Audiences will find out what is "darker" about the franchise on May 1, 2015.