Marvel was so surprised by the "phenomenal response” to the Hulk in The Avengers that one executive revealed last spring that the studio is considering a third solo movie for the character. That was seemingly reinforced earlier this month by a rumor that an adaptation of the "Planet Hulk" storyline could spin out of the 2015 Avengers sequel.

However, ComicBookMovie reports that Joss Whedon admitted recently at the Dublin International Film Festival that another Green Goliath feature would be a difficult proposition. Asked whether it would be possible to make "a good Hulk film," the writer/director replied, "Yes. But it would be very, very hard."

"Hulk is a tricky son of a bitch. He’s the Claudio of superheroes," Whedon continued. "Because the problem is it’s a very popular character, but it’s not a superhero. Half of it’s a superhero, half of it’s a werewolf. And you can’t structure it like a superhero movie, you can’t light it like a superhero movie. How do you develop that? It would be extremely difficult. The one thing you would have in your favor would be Mark Ruffalo. But right now I don’t know if they have plans to do that or not, because he works so well as part of a greater whole, but by himself, it’s tough. I don’t envy the guys who went before."

Of course, some might argue the question is flawed, as 2008's The Incredible Hulk certainly qualifies as "a good Hulk film." Maybe not great, but certainly good.