My issue is that this is being pushed as a game creation tool. I have problems with that since it is restricted between monthly subscribers or free users.
If your child wants to learn to make games, there are free tools out on the net that don't need a monthly subscription. Even RPG Maker XP can be a good tool for a budding game designer. If you are wanting a good community, GarageGames is a great community and tools to make 2D & 3D games. (Granted, its $100 for the basic things but are very user friendly)