Water (reflecting and refracting), shadow mapping, particles (rain, smoke from blocks), transparency (the blue cube on the ground), normal mapped terrain, physics, etc...
Firing a sphere into a stack of blocks. The blue boxes are areas acting as 'anti-gravity' to stir things up a bit. :)
We've included the physics debug viewer that JibLibX is using in their samples. Especially handy with invisible trigger volumes.
View terrain quad-tree bounding boxes.