Thanks for the 'keep it growing' and the suggestion!

Mercuryus, I used the fly action from your contribution, thanks for that.
(It is not implemented in the game of this course, though.)

The course has been five days, 6 hours a day (including pauses for lunch and sports of course!), where the kids of the age from 10 to 14 learn a bit of the tools each day while parallel collecting and discussing ideas, and producing models, sounds, skins for the game and its story. After that we find an agreement about the story's final shape and produce terrains, levels, texts and the rest of animations and models needed for the story.
The kids request some functions for their visions and I have a look whether I can add one or two of them. I had to add several functions, because the given set of functions was very incomplete.

When I started the game editor, I did it badly organized, because I was unsure about which functions are needed. But, I think I'm on the right way with the quest system, now. There is still a huge area for improvements, but it is a base for making simple games where the kids can enjoy adding quests, models, sounds, texts, levels and even (very) small functions or modifications within functions etc.

msl_manni,
I thought about Newton, but I have no experience using it.
PhysX isn't free, and I don't want to force the kids to buy anything, in case they want to continue making games after the course.