- The numbers from 1 to 30 at the left bottom are the ones of stages of this game. Please click these numbers.
- If you get made the same shape of the blude closed curve on the upper figure as is the right below small figure, then you clear the stage. You can only use Dehn twistings to transform figures. You must consider the orientation of the curve.
- If you want to make a right angled Dehn twist, please click the light green curvein the picture. (If you want to click the curve B and D, you need to avoid the area the other curves exist.)
If you click [right twist (+)], you will get [left twist (-)] and the curves A - E turn to pink. In this mode you can make a left angled Dehn twist.