@gunslinger You head up a "Command and Conquer"-style realm where absolutely nothing happens without your input. Your job is to set up your little fiefdom with the various production buildings and whatnot. To do that, you need to attack what's going to be your future keep. Then you need to faction up with a particular group. Then, you join an alliance to get supply keys. Supply keys are amazing because you can get cool toys that wouldn't be normally available to you unless you paid gold for them.
Gameplay-wise, it's a simple point-and-click, and hold still while they fill your order.
This touches on some really good concepts, yet is simple enough that a kid could follow it. You could write something similar with more diverse characterization and more advanced concepts, and release it as full-on educational software.
Possible features:
LAN Arena so the kids can fight each other.
Internet Arena, customizable by the instructor.
Reward Animations for doing a good job or Arena victories (In 3D!)
BGM of some sort.
But whatever you do, have fun.
This game has a command economy, so be forewarned; it needs constant supervision to stay active. They should put in a queue for items to be produced + if you agree.