So far this is one of the worst sudoku games I've played. There are no automatic pencil marks available. Adding pencil marks is a painful process, I didn't even know I could do it until I clicked on the pencil thing by accident. When I want to highlight all of a number I have to either click on an original number or click then drag my mouse away to get the number selector pop-up to go away.
 "Mix Sudoku Light Vol.1"){kind=icon}
 "Lightbot 2.0"){kind=icon}
 "Spellblazer"){kind=icon}