IE 10 Test Drive - Particular Acceleration

In this page:

http://ie.microsoft.com/testdrive/Performance/ParticleAcceleration/

If I open it in IE 10 and click on the center of the particles, they don't explode.

If I open it in Chrome 21 and click on the center of the particles, they explode.

Why one does explode and another does not?

Thanks for your kind help.