DougX here, developer of the game. Thanks for the compliments.

In response to qubodup's comment in this thread, it was my intent
for the JavaScript source code to be open license. I just forgot
to mention it anywhere!

I've added comments in each source file to that effect this morning,
and on the home web page also. Thanks for reminding me.

The game is a proof of concept for HTML5, and as such it's more about
programming than game play. This also means that there is no way I
could have done it without open license artwork. No way at all! So
thanks to everyone here for your hard work and your contributions
to the world of open art.

-D