ez4u2c

Nicely polished, well executed, very playable. Thanks for sharing!

You can adjust the difficulty level by changing the number of steps (constant in HDbg). Also if you haven't started removing any squares and you need a clue where to start, shift-click on an empty space and the last step that was placed will change color to red, showing the end of the string of squares as they were placed on the board. (Thanks for playing!)