Checking out the other highly rated games in the Chrome web store I came across a couple cool things to play with.
Sand - https://chrome.google.com/webstore/detail/pdknckljjbdpkhgmcokoahffbdinafbo/reviews - I can't describe it. It's pure play, mixing sand and water and oil particles and setting them on fire and stuff.
Even better, though, was Little Alchemy - http://littlealchemy.com/ - you start with air, earth, fire, and water - and mix them - and see what you can come up with. Combine them in the right ways and you can make snowmen and zombies. Who knew? Although part of me says, "This is just a sparse matrix of combinations that I'm filling in," another part of me says, "When am I going to stop? This gets harder and harder as I go along," I still sat there and tried to come up with new combinations for hours. My daughter loved it too: 'the best game ever,' she said. Hey, what am I, chopped liver?