The Circle Puzzle appears exclusively in Version 3.0, after putting the 2 metal pieces in the attic room. It consists of 5 connected circles.
Solution[]
Stepping on different circles can highlight one or two circles at the time. Standing on the middle circle will clear the highlighted circles.
The order is: Right, Left, Down, Up, Down, Right, Up, Right, Up, Left, Right.
After you get all the circles highlighted, a door will appear which takes you to the Blueberry Farm.