While not a real sequel to the 2003 Hulk movie, it feels like one. Bruce Banner is still on the run from General Ross, trying to get rid of his Hulk persona. Meanwhile, General Ross is tinkering with a solution to the Hulk problem that proves to be a cure worse than the disease.
I was never much of a fan of the comics that depicted Hulk and Banner as two entirely different beings. Still, this movie actually makes the Hulk into something likable, a big monster with the mind of a very small kid, not dumb, just young. Which makes me wonder why nobody in the comics ever went much further with the concept.
Imagine the Hulk really born after the Gamma Ray explosion that transformed Banner into Hulk. If the two are really distinct personalities, then it explains why Hulk has the mind of a very small child, just being born and everything. But instead of ever showing the Hulk persona growing independently from Banner on his own, he was forevermore this childlike monster. This led later writers to abandon this concept and depicting Hulk as something that is still Banner deep down, only with much of his rational mind gone and full of aggression and rage.
But back to the movie, this one is more action-oriented than the 2003 Hulk movie, but still has similar depth in the character department. Which makes it a much better paced movie who gives equal time to the Hulk and Banner, unlike the first one, and whose final villain is a much more convincing enemy for the Hulk than the father-turned-monster of the 2003 Hulk movie.