I need to find out the title of a movie I saw as a kid in the 80's (possibly late 70's movie).

Imperfectly remembered...
Family movie in which a small boy is found/adopted, turn out he is a robot/android and a test subject for the government.

Remebered scenes:
Kid being taught baseball by the dad, and discovering that he can throw the ball really far, and then later playing a game and not throwing the ball- thereby leaning a lesson about love and vulnerability.

Kid (captured by goverment) watching a whole bank of TV screens and videogames,

He is eventually captured by the government and escapes somehow by flying a jet, and then parachuting out of it into a lake. Everyone thinks he's dead- but it's OK because he's a robot :)

Please please help! Any suggestions appreciated!