Millionaire kid developing a game

Question

There was an old movie I saw when I was a child. A genius kid develops a game which sells for a million dollar or something, and gets rich off it. He couldn't handle the amount of money and buys lots of unnecessary things, losing his girlfriend in the way. In the end he understands the value of hard work and sells all extra things.

Answer 1

I think the movie you're looking for is Matt's Million, which was a TV movie, released in 1996.

Synopsis from Wiki on this movie:

The story was about a boy called Matt Collins, who became a millionaire at the age of 11. After developing a successful computer game, which sold heavily in the Far East, Matt receives a cheque for just over £1.25 million from his family solicitors. Upon the initial reaction of shock, Matt carefully purchases some select goods, namely two bikes and a rented Rolls Royce, driven by his own personal chauffeur, Henry. As the series progresses, he later discovers money makes life harder than you think.