How To Play the Falling Sand Game
You get a dark box and a list of elements. Pick one, then draw inside the box with your mouse or finger. Each element follows its own simple rules, and the fun starts when they touch each other.
- Sand, salt, stone and gunpowder fall and pile up into little hills.
- Water, oil, acid and lava flow and spread out to find the lowest spot. Lava is thick and slow.
- Wall, wood, ice and plant stay exactly where you draw them.
- Fire, smoke and steam drift upward and fade away.
Hold your finger or mouse still to keep pouring. The Brush slider makes your brush bigger or smaller. Pause freezes time, so you can set up a tricky scene and then press Play to watch it go. With a keyboard, click the box and use the arrow keys to move the brush, Enter to pour, P to pause, and the bracket keys to change the brush size. Number keys pick the first ten elements.
What Your Score Means
There is no timer and no way to lose. Your score is the number of reactions you have discovered out of 15. A reaction happens when two elements meet and something new comes out, like lava and water making stone and a puff of steam.
- 1 to 5: you found the obvious ones, like fire burning wood.
- 6 to 10: you are mixing things on purpose now. Nice.
- 11 to 14: you are hunting for the sneaky ones.
- 15: every reaction found. Your Reaction Book is complete.
The Reaction Book keeps your all-time list in your browser, and it shows a hint for every reaction you are still missing. Share your total when you are done, or save a picture of your best creation.
Tips To Improve
- Build a container first. Draw a cup out of wall, then fill it. Liquids stay put instead of spreading across the whole floor.
- Heat things up. Fire and lava cause most of the reactions. Try touching them to everything.
- Be patient with steam. Hot vapor floats to the top and only turns back into water after a little while.
- Use oil as a fuse. A thin line of oil carries fire across the box, which is handy for lighting gunpowder from a safe distance.
- Give plants a drink. Draw a small sprout, then pour water next to it and watch it spread.
- Read the hints. Every locked reaction in the book has a clue about which two elements to try.
Fun Facts About Sand, Lava and Salt
Real glass is made mostly from sand. The sand is mainly silica, and when it is heated until it melts and then cooled, it turns into glass (source: Corning Museum of Glass). That is why sand touching lava in the box sometimes turns into shiny glass.
When real lava flows into the sea in Hawaii, it cools and hardens into new rock, and the meeting of hot lava and seawater sends up big white steam plumes (source: USGS Hawaiian Volcano Observatory). The lava and water reaction in the box copies that idea.
Salt lowers the temperature at which water freezes, which is why towns spread it on icy roads in winter (source: American Chemical Society). In the box, a sprinkle of salt slowly melts ice back into water.
