Okay, I'm late with this, because I actually saw this movie on it's opening weekend. It was kind of exciting, because I've never seen a 3D movie before. I was worried it would give me a headache or make me nauseated (which tends to happen to me in movies anyway, because yes, I'm THAT LAME). But it was actually really cool! I'm going to make it a point to see some more that way.
Technology aside... man, I really loved "UP". Just like Ratatouille, I didn't initially have any interest in seeing this movie. The character didn't look likable at all, but I should have known better, since Pixar takes unusual heroes and gives them a lot of heart. They made me connect with a fish and rat and a bunch of plastic toys, so a grouchy old man should be no big deal.
Here's an interesting NYC online article about the character design for the movie. It says better than I can how hard they world to make the characters awesome. But like all really good books and movies, none of that hard work is obvious as you're watching. They're just real and engaging.
Within the first ten minutes, I was-- well, I'd gone through a whole Kleenex --but I was completely invested. Carl wasn't immediately likable, but he was completely sympathetic. He really went on a journey (no pun intended) through the movie, and it was incredibly satisfactory. Russell, the Wilderness Scout, was resourceful and ingenuous and open-hearted and wonderful. He went right to my heart, so it was entirely believable that he would work his way into Carl's too.
The dogs were, of course, my favorite part. Doug won my heart right away, but all the dog humor was awesome and right on the money.
Despite the quite emotional story arc for Carl, there's also exciting visuals, action, and adventure. The movie is visually beautiful. Gorgeous colors, and I thought that, with so much of the action being on all three planes (i.e., vertical was a big deal in a movie called "Up.") I felt like the 3D format served the movie well. It wasn't just "because we can" special effects. It really enhanced the whole visual concept.
That's my way of saying, if you can get to see it in a 3D theater, it's totally worth it. And if you can only see it in a normal theater, it's still worth seeing on a big screen. But go see this movie. It's REALLY good.