use the up and down arrow keys to switch blocks and the mouse to place/drop the block . if you press "C" it clears the screen and "P" freezes every thing. Once you have created your structure press "S" to save it and the press "space" to generate a wrecking ball then SMASH EVERY THING you can toggle particles on/off with the slider then once your done smashing you can start over or press "R" to rebuild the structure
NOTE: there is tons of lag with and with out particles and downloading might make it worse but on my home made webbrowser it works fine so im not sure
