You should be able to fly in creative mode.
HN user
mastercoms
We're actually working on this, first with a rewrite of our item/block behavior system to be modular and moddable using lamdbas.
Then we will be adding a way for plugins to provide new textures in resource packs.
Once that's all done, we will create a client Forge mod to allow for plugins to add new blocks rather than reuse existing ones.
We also have a pretty nice modular system for AI tasks, but it needs more stress testing with a pathfinding implementation before we start finalizing the API for it.
A lot of people are recommending Scratch, but I am going to recommend Construct 2. It is an awesome engine for making HTML5 games. It is visual coding so your nephew will have no problem with it. https://www.scirra.com/
Of course, listen to what pvaldes said also. Designing a game first will be better.
Also, I would recommend Teamviewer for you guys to use so he can share his screen and you can interact with it.
He is trying to make his sentence natural. As in, he is talking, and correcting himself by saying "good, hmm, uhh, no!, exceptional!"
When I think light, the last thing I think of is ads. Ads will make your app feel bloated to users.