Really cool design/concept! I love the polish and the graphics, but I do have a few critiques: I think the symbols on the circles don't really tell you immediately which ones they flip, which can make it a lot hard to construct a sequence of how to solve the puzzle in your head. I think that while it would be less elegant, if they had little arrows or dots pointing to the ones that they were going to flip it would feel much more intuative. I also think the circles flip a little slowly, but that's just my preference. Other than that, really great entry :)