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.
migrated from scifi.stackexchange.com Jan 7 at 16:10
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: