This was an entertaining movie, with good acting and an interesting story, but I would have preferred a plot with more tension. Also, near the end when he became a young-looking, small baby, the movie lost its credibility, since he started as an old-looking, small baby. He also started out as a baby with diseases associated with old age, but near the end he was shown as a boy with dementia, even though he was supposed to be getting younger and wiser. It was disappointing to sit for 3 hours through a decent story and good acting, and have the ending not make sense.
I wasn't expecting a great movie but I did expect something different in the way of plot. I think the movie will be appreciated far more by those who loved the series than those of us who only caught an occasional show. To me it seemed to drag a bit from time to time, as well as last about 15 minutes longer than I'd preferred. I think the ending would have been too predictable if the movie had been less than 2 hours, so it was stretched out in an attempt to convince you that the predictable ending wasn't going to happen after all.