Undo button

Love this game.
It starts with easy versions- then progresses to the 12x12s- gives a new player some orientation time.
The labels are great for color blind individuals, and for instances where same colors with different shades are hard to tell apart (for older eyes).
The game screen gets very colorful as the game progresses- nice.
...also makes me think esp when playing the more complicated versions- an exercise in logical thinking.
There is also an option to control the background color and the brightness of the screen- another nice.
I gave four stars instead of 5 because I think an undo button would be nice for times when I get careless, or go too fast, or when a playful cat jostles me, and my finger goes to the wrong space when drawing the lines.
Great game!

yoyed110 about Draw Line: Branch