Take a look at what Rebol did in the late 90s. They have a DSL called "View" for making user interfaces with your scripts. Rebol itself shipped with a program that came with a ton of sample applications including Tetris. The creator of Rebol (Carl Sassenrath) was also big on the Amiga scene and envisioned what he called iOS (internet operating system, not the Apple iPhone OS) where you would do stuff like load a web page by just running the page's Rebol script iirc.

It never took off for various reasons. For one, the language was a bit like lisp, but with brackets. More importantly, it was commercial and then closed source for too long when Perl was really taking off.

Long story short though, whatever language you implement should have extremely high level primitives for simple GUI widgets. Forget Qt and Windows Forms...there HAS to be an easier solution. I can see how Rebol did it and surely you can make something like that possible.