2 missing scenes might have improved this....(SPOILERS)
1. Maybe a warm, more reconciling scene between the boy and his mother's brother...especially just before the boys's return to Mars, with the brother sharing some memories of the kid's mom with him. Instead of having the guy merely used as a plot twist prop, then promptly forgotten about....
2. They spend the second half of the film yanking on your heartstrings over the romance .....then brush it off with perfunctory, rushed goodbye between the boy and girl...(the way it's staged, you'd think she was just someone who lent him bus money, instead of the love of his life...) They seem to imply at the end that she's in astronaut training.....so why not, for the sake of the audience whose tears these filmmakers strenuously begged for, throw in a 'One Year Later' scene and have a grand huggy-smoochy Martian reunion for the boy and girl? The way it's filmed now, the movie says the kid's return to Mars with his father is enough of an emotionally satisfying gesture. Sorry....but that didn't do it for me.....call me old-fashioned, but I wanted to see the kids back together, romping through the Martian dust, maybe racing each other in the dune buggies.....