My country has rockets where the robin sings

Year 2000. Brazil was partially devastated by the Third World War. An immigrant family arrives in a small town, which they call "I Forgot." The trio is recruited by an indigenist to pretend to be indigenous during the visit of a general. In the dilemma of integrating into the system or preserving individual freedom, the family moves toward disintegration as the city prepares to launch a space rocket.