I don't entirely disagree with the reviewers, but I think I enjoyed it more than the average viewer enjoys any movie. Partly because of Cusack, and partly because I can't help but feel empathetic with children. John Cusack is an actor whose face is a movie screen on which emotions are projected. Neat trick. He even manages to give an inkling of the internal emotional state of a character when he's holding a poker face.
And his sister Joan Cusack is in it, an actor I think has never gotten her due, or the kind of part that would bring her to the foreground. I'll even excuse her the dumb cell phone commercials. In this movie she's the vinegar in the salad dressing, a counterbalance to John Cusack's wide-eyed earnestness.
So maybe the Martian Child is a Lifetime movie with better production values and fewer douche commercials, but it held my attention and had some really good scenes.
Unfortunately where they really missed the boat is in making the John Cusack character straight. David Gerrold is gay, and like a lot of gay men of a certain age, adopts a child. Melissa & I had a teacher in high school who was gay, and adopted two boys. You can't generalize from an anecdotal experience, but to me it seems, having watched our teacher with his kids, that there is a particular chemistry of a gay man with adopted children, that is worth exploring in a movie. Or at least, it's worth acknowledging.
I don't know if Cusack didn't want to play the role gay, or if the money people didn't think a queer adoption would fly with the viewing public, or if the writers just went for the obvious, and added in a dead wife and Amanda Peet as a love interest because they thought it would punch the story up. But they did what they did, and given how much this movie seems to have failed with critics, I don't think it did the movie any favors.
And it's a shame that Gerrold's book, which told the same story with such depth, couldn't have been made into a better movie. Gerrold was one of the producers of the movie, so he was a participant in the train wreck; maybe he wanted to make a big budget movie with broader appeal than it would if it was true to the original story.
Whatever the reason, it's a shame, because the story itself is compelling.