> If someone were to make something like this a step-by-step tutorial/template appropriate for a classroom setting it would be HUGE.
(emphasis mine :-))
That's the first thing I thought. I teach kids to do creative/interesting things with computers. It's hard to get them writing code[0] (it's not a classroom--they come voluntarily and explore what technology topics they like), one of the older (14) kids started out doing that, however, because he wanted to write Minecraft mods. Those are written in Java, in an Eclipse environment working on a decompiled (and only partially annotated) version of the Minecraft .jar. That was not how I envisioned a gentle introduction to computer-programming :) But he was persistent, and got it to work. This only goes to show what's really important: not if the language is simple, complex, elegant, whether the subject matter is easy to grasp, no. It's just a matter of whether the thing they need to learn is on the path towards a goal they really really want to achieve[1].
But yes, Minecraft is a huge thing among these kids. Others are cobbling together multi-player servers from scrap computers.
While in a sense, brooksbp (sibling comment) is right, there's a LOT going on in these 580 lines of code (I haven't looked at it yet, but I can imagine), 580 lines is not that much either. And if it's something they can run, edit, run, mess around with, see why it broke, edit, run, etc, that's enough to get started. They don't need to understand the whole thing right away. In fact even something as simple (and hardly programming) as changing the colour or textures is awesome because it teaches them that whatever's going on behind those graphics is yours and yours to control (unlike, say, the TV or their aunt's iPhone).
That 14 year-old kid is currently experimenting with Unity, trying to make an actual game. Unfortunately, I haven't had time to get acquainted with that environment myself, so I can only give him general advice. I'm way more comfortable with Python (especially a mere 580 lines of it :P) so who knows.
[0] Which still mystifies me, I was writing my first lines of BASIC at the age of 9, without help from my parents or anyone except library books and magazines. That probably makes me an outlier, but enough children pass through here that I'd expect to see at least maybe one or two. I guess it's different because back then that machine (an Amstrad PCW) wouldn't do anything interesting except word-processing unless I coded it myself.
[1] That was actually a big lesson for me :) I kind of knew it to be the case, but witnessing the process really nailed it down for me.