Some interesting ideas rattle around in this Spanish sci-fi movie about Álex (Daniel Brühl), a scientist building a robot modeled on a real child. Rejecting other kids as “too boring,” he decides on Eva (Claudia Vega), the 10-year-old daughter of his former flame, Lana (Marta Etura), another scientist.

Trouble is, the characters are thinly conceived. Eva is the kind of cute, smart-aleck kid who’s been around at least since “The Goodbye Girl” in 1977. Álex is withdrawn and wary, Lana is warm but conflicted.

In the last half-hour, themes start to gel. The final scenes are so good, even moving, that they make the earlier stuff look better. But a film concerned with the nature of emotion needs human engagement throughout.