tl;dr this is a liquid simulation toy. This starts with four colors of different densities (so they self-organize into layers). Clicking allows scooping up a ball of the liquid. I consider this pretty to watch, like a laval lamp that I can also throw globs of.
You also have a settings UI, where you can change (among many other things) what clicking does. I find it most interesting to switch to "repel" - the repulsion forcefield turns to be an universal tool for mixing and separating the different liquids, depending on how fast and precisely you operate it. Fascinating.
