Some time ago, Valve had the only popular physics engine, and used it for their Half-Life 2 series. Now, several years have passed and there are some mass physics engines that can compete with it, and are even better. One example is the Crysis physics engine! Very cool! Enjoy!

It doesn't make much sense to me...guess I'll have to play this level a couple of hundred times more, before I get close to this guy's solution. Amazing!