Upside down is a steaming hot mess. I'll start with what I liked and end with what I didn't. Firstly, Jim Sturgess outdoes himself in his role as he has done in previous roles I've seen. He performs so effortlessly that he seems TOO GOOD for such a messy script. Kirsten Duntz was decent, but nothing to get excited about. It was nice to see Timothy Spall as a protagonist for a change.
The visuals, directing, and cinematography were flawless and inspiring, executed with perfect precision. It was almost like James Cameron directed this with a Nicolas Sparks script. The science behind the concept would have been intriguing if it wasn't so flawed, but even if you were to suspend your belief of how the worlds work, you would still have characters with little development. Sturgess did the best he possibly could with such an underdeveloped character, but it just wasn't enough to bring the plot together. He and Dunst had chemistry, but we are told they love each other and we must accept that with no other background other than they met as kids. Sturgess himself is endearing and that translates into the character he played, but Kirsten's character we care little about. If they got together it wouldn't really matter and if they didn't we'd probably only feel bad for him, but not that bad.
The ending was abrupt, anticlimactic, and forgettable. I wanted to like it more than I did. For Sturgess and the breathtaking cinematography, I'll give it a 2.5 out of 5 stars. I just couldn't get it to 3. (Watch If Free)