It is always fun to play around with cellular automata. especially when there is an UI to mess around with the parameters :-) It took me some time to wrap my head around the cell selection and different rulesets principles though, and I wished I understood it before resetting the page for the first time because I found a nice combination that made ever 2x2 square shoot a vertebra-like column that periodically collapsed and now I cannot find the settings for it again...
Also, while I think the were a bit too distracting for playing around with the cellular automaton part, I did like how the snowflakes looked, especially since they seem to be generated from within the tool itself :-o Maybe I just missed it, but is there a way to access the ruleset(s) use to generate those?