I don't know why I'm keeping all this frustration to myself! You lot have a go. It'll keep you out of mischief for a while.
Click the blue cross above the black screen. Then click the Aqua-coloured characters. The idea is to clear the screen by clicking connected pairs. They can be connected with only straight lines and you are limited to turning two corners. ...like up and left, or down and right and up. You can't go up, left and down and right, for instance.
http://www.xiaoyouxi.com/down/soft/681/5861.htm