Falling Sand!

There is this game on the internet (you need java by the way) called Falling Sand and there's lot's of variations of it on there. It's very simple and extremely fun too. You can make land, sand, water, plants, wax, etc. Nitroglycerin, fire and other things bring ruination and you can build and destroy without any mess! But the best part is you can summon zombies for your creation. Yes, zombies!

"Falling Sand Game", also "Hell of Sand", is a Java applet first found on the Dofi Blog, later enlarged and rehosted by Chirag Mehta and then again by Falling Sand Game. The game has been popular on community link sites and forums like Falling Sand Game, Digg and Delicious and involves four main falling particles: sand, water, salt, and oil. Each of these particles have special properties that can be manipulated; among these include burning, desiccating, growing, eroding, and more. Along with these four, main particles are auxiliary environmental manipulators: Wall, Fire, Plant, Spout, Cera (or wax), ???, and Erase. By putting these together, one can thoroughly enjoy the modeling and the construction of very complex structures and systems. There is an additional special feature that can be turned on, off, or told to remain in place. This is called the namekuji which means slug, and reacts naturally for the properties of a slug when salt is poured onto it.

Several different versions exist, varying from applets with zombies, or human bodies, that have their own unique properties to applets where auxiliary environmental manipulators have additional properties.