I watched this movie expecting what I got: good sci-fi cowboy stuff. What really surprised me was that Kurt Russell did such a great job with an extremely limited role.
Imagine trying to act under these two restraints: you have hardly any dialogue, and because you are playing a hardass, military robot, you are not allowed to show emotions using facial expressions! Howzat? Kinda like asking a diva to perform a great aria while gagged and duct-taped. In spite of being verbally and expressionally handcuffed, Russell pulls off an incredible characterization. His robot becomes human, in spite of the constraints. Great job!
As usual, Jason Isaacs insures that he will go down in history as a great portrayer of the consummate villain--the one you'd love to see drawn and quartered. Connie Nielsen was sweet, soft, motherly, and gorgeous. I'm not sure how much of my impression is based on her acting and how much on her physical beauty, but it was hard to take one's eyes off her. Unfortunately, Gary Busey's role was too small and limited.
Much of the plot is quite standard, with a fair amount of weaknesses, but as it does have a sci-fi comic book feeling, I don't see what's wrong with a few weaknesses. By the end of the story the good guy wins, and the appreciative audience receives a great deal of emotional satisfaction. Yes!
The sort of feeb who thinks that Russell didn't do a good job of acting is the same sort of feeb who missed the whole point.

This "movie" is more like a music video. Kusturica said in an interview from 2004 that when he is making movies, he feels like making music, and when he is making music, he feels like making movies. The best thing in "Promise me this" is the music, written by Stribor Kusturica.
Kusturica said in the same interview, that for him the dialogues in the movies are like noise. "Promise me this" has very little "noise".
I liked "Life is a miracle". It was also like music video for the first 30 minutes and at some points later, but it had a beautiful plot. "Promise me this" has no plot. I was awaiting this movie with big expectations, because I've read, that the script has been written by Ranko Bozic - one of my favourite scriptwriters, who participated also in "Life is a miracle". Ranko Bozic writes great dialogues, but for Kusturica they are "noise", and much to my regret, I saw only two dialogues, which I could identify as written by Ranko Bozic. The other part of the script was used by the director for making his chaotic music video for the music of his son Stribor.
Gordan Mihic (the man who wrote the scripts for "Time of the gypsies" and "Black cat white cat") said in an interview, that Kusturica never follows the script. "Black cat white cat" was the only script, for which Kusturica said, that he will not touch it. According to Gordan Mihic, after all Kusturica comes back to the script, and if he doesn't, he doesn't make a good movie. And I think this is the case with "Promise me this". He should have followed the script of Ranko Bozic.
"Promise me this" is billed as a "comedy", but there are very few moments, which made me laugh. The comedic moments are in the same style as "Black cat white cat", but are not that funny at all. I think the difference comes from the fact, that "Black cat white cat" was written by Gordan Mihic.
However, I know some people, who liked "Promise me this", they find it very positive movie.