Yeah, it's really unfortunate. I haven't had a look yet since there's not much I can do until after the judging period, but I'm thinking maybe the tile they spawn on is accidently marked as collidable or something
Programming games aren't a unique concept, you should check out the excellent games by Zachtronics, although the stories may be a little mature for a young child. The assembly-like language here is very much akin to Exapunks or TIS-100. Although it's so simple in this game that I wouldn't really say you can learn anything from it