This a great idea for a game for a variety of reasons. From a pure game design perspective, the constant shift in the rules creates the kind of safe uncertainty that is perfect for game motivation. It also is at the "goldilocks" level of difficulty that established Flow and a feeling of satisfaction when you get good at each new set, only to start the loop over again when they change.
But it is also a good game for another reason - the ulterior motive of the game designers. If this can really get people to question their ideas about beauty and develop a broader perspective on it, it would be a fantastic evolution of our culture. I hope they are successful in this, and I suspect they will be, bringing me to my third reason and the purpose of my post today.
This is a great application of the cognitive science that underpins human factors. One of the hardest things I have to explain to my students/clients is that people don't learn and remember strictly defined rules and processes. Everything is a fuzzy statistical aggregation and conglomeration of evidence with some things being more likely than others but little is impossible and little is mandatory. We can imagine a purple, three legged, 6 foot tall, half cat half dog - even though we have never seen one (I hope!!). And we can also stare straight at the most normal looking dog we have ever seen and for a moment think it is something else.
This is why we are able to play Pretty Ugly. If rules were absolutes, we would learn the first set and get stuck on it. But as long as our minds remain fluid, we can accept the fact that rules can change.
Of course, this is not a perfect ability. When we have a personal investment in a set of rules, it is much harder for us to give them up. This is what happens when a new scientific discovery comes out that questions a strong value. When we learned that the earth revolves around the sun - well, that didn't go so well. More recently, evolution is still not universally accepted and global climate change is quite a sensitive topic.
So if we can get to people before the set of rules becomes strongly ingrained, then it is possible to set up their cognitive model as a fuzzy, loose system of changeable constraints. Hopefully, enough young people (and open minded old people) will play Pretty Ugly enough for this to happen.
Stay loose !!