Apparently your browser doesn't support Java or it may be a version that's not compatible with the program. Problems have been reported conserning some versions of Firefox, but I had no trouble at all.
You draw walls that alter the flow of different substances, like this
Yellow: sand - flows, destroys spouts, may douse fire
Blue: water - flows, douses fire, makes Plant grow, makes Namekuji grow
White: salt - flows, makes Namekuji shrink and (eventually) die
Brown: oil - flows, ignites easily
Gray: wall - solid, blocks the flow of substances, doesn't ignite easily but I think I managed to burn it before with longer exposion
Red: fire - burns stuff, tends to move upwards as long as there's material to burn
Green: plant - grows in water, blocks
???
Light blue: spout - solid, creates water beneath it if there's space
Light beige: cera (wax) - solid, ignites easily and droplets fall from it when it melts
Pink: ??? - creates an explosion that destroys everything on the screen besides plants and the Namekuji, only stops when all possible areas have been wiped (which means when Namekuji is around, it never stops at all...)
Black: eraser - wipes everything it touches besides Namekuji
Namekuji: a creature of a sort, it wanders around the screen if let to move, tries to find it's way to water but is afraid of salt, grows in water and may turn big enough to cover the whole screen O__O;; may be set on fire and really hard to douse, eats away everything it touches, explodes into little balls upon dying and a new one is created, may be set immobile or off
