Overturn is floor 3 of expert challenge mode and is in world 6 of story mode in Super Monkey Ball Deluxe. It is made up of a square shaped platform with a smaller, square shaped hole in the center (like a square dohnut). The half that the player begins on is stationary, however the opposite half rotates. This floor has a blue and a green goal.
This goal is on one side of the rotating half opposite the green goal. The half it rests on is textured the same as the stationary half. When the platform rotates to this half, it will momentarily stop, making this goal easier to reach.
This goal is opposite the blue one. The half that this goal sits on is textured blue, as apposed to the norm of wherever it is found. This half will not stop at all, unlike the blue goal, so the goal must be reached quicker.