The reason I like games is because they use _intrinsic_ motivators. To me, this is violating the whole principle. This is basically bribing a child with money and gifts. He said it himself, "It made me more interested in exercise because I got money." Games are wonderful because they give meaning...this is not meaning. A game should make you feel part of something bigger than yourself and make you want to collaborate and work hard simply for that good feeling.
Look at games like Foldit, where gamers spent hundreds of hours folding proteins for scientists. Did they get cash? No. Did they win a gift? No. All they got was the fuzzy, warm feeling of collaborating with hundreds of other players and recognition when they succeeded. What this child is participating in is not a game in my view...it's just a glorified bribing system with buzz words like "points."