Sorry, at the moment here you can only find a simple test if in your browser the Java plugin with 3D support is working.
Because we were in a hurry we hacked together our own home-brewn format and loader (instead of fiddling with existing VRML/X3D things).
We plan some single-agent fun games located here in forthcoming XiStrat releases.
Be sure you installed the Java 1.6.0_12+ Plugin and Java3D.
Here are some nice graphs for you to look at (try out translate, rotate, zoom and CTRL-leftMouseClick):