Just tried your system out. Found a few bugs.
I coded an infinite loop. Then I typed "run" and then I realized that there doesn't seem to be anyway to halt a program once it is running. There must be a big red octagonal button on the screen with the letters "STOP" in it that actually stops the program.
I tried to code an IF statement. I had to look up the syntax because "if i 0 then goto 2" got a syntax error. I can almost forgive using the C like "if()" for the if statement but using FORTRAN like "LT" for "" is pretty nasty if you ask me.... But, you didn't :-)
You have a "declare record" statement when just "record" would do. Using "declare" make sense if you are planning to add more things to declare, otherwise it is just a waste. And, seriously, no "for .. next" statement, no "if ... then ... else..." statement, no while statement, no multi-line statements at all. I see that you have reserved some keywords for those so it looks like you are planning to add them in the future. Please, these are critical parts of any language. I know for a fact, having done it, that it is f(&#$@#*$&^King easy to implement those compared to some of the things you have already added.
I tested what would happen if I typed "run" for a program that has a syntax error. It went away forever. No error messages, no output at all. It just stopped reacting to the keyboard. This is a serious bug.
The documentation is really really really poor. Very few examples. No real introduction. You use things like "boolean-expr" but do not define that anywhere it the document.
"turn" is great, but you need left and right also. Kids understand left and right. Positive and negative angles are a bit harder for them.
Palettes? Really? It is very hard to find a computing device that can run a modern browser that is not using RGB pixels. Why put this ancient cruft in the way of kids? Color values are RGB in the range 0 to 1. There are no palettes anymore.
Sprite maps? Nostalgia is an addictive drug, but like all drugs it is damaging when used to excess. Why not just have a place on the screen to browse and drop graphics that can then be used in your program?
I've written an ANSI standard BASIC compiler, I've written a Logo interpreter (or 2 or 3 :-), and I've taught courses in which the final project was a Lisp interpreter. In fact, I've written many compilers, interpreters, and even a linker once. I've also used both basic and logo to teach kids aged 5 to 12 to program. And, I have to say that while you have a good idea your implementation is far from ready for use by kids if I can break it in 5 minutes doing exactly the kind of things kids do.
It looks to me like you have focused on the "cool" parts, the graphics and the math library, but have skipped, or at least skimped on the critical part. The critical part is creating a system that works, followed by the documentation needed to use it.
BTW, WTF is "proof" for? It is left over from back in the day (your nostalgia is showing...) when you actually had to type in code that was published in magazines. OMFG!!!!! We live in a world where magazines have websites (in reality a few websites still have magazines) and flash drives are nearly cheap enough to show up in cracker jack boxes (yeah... I'm old, I learned Basic and Logo on an Univac 1108a :-). We do not do that anymore!
You have a good idea. But, shake off the nostalgia and make something that acknowledges the 21st century.
Yes, I know I have been harsh on you. If I didn't really like the idea of what you are doing I wouldn't bother to find the flaws, let alone spend the time to point them out.
I've recently managed to eliminated the use of paper in all the classes I teach. Doing that has really pissed off the English teachers who still insist on paper and give tests using blue books.