What kind of IDE/environment are you using?
I think the biggest hurdle is not the language choice, but how to get things to run.
My first language was Logo. Couldn't do much with it, but it was fully interactive, which meant that you got immediate feedback as soon as you pressed Enter.
I've recently had to make a simple graphics language for my day job, including an interactive editor which ran the program (= redraw the image) on every change; feedback while you're typing. The language is quite strict and unforgiving, but if a similar language could be made friendlier, it could be a great kids' language.