Would save clicking Exit, puzzle number, play. Thanks

... the levels need a simple clear-all button, please.

... I've done a lot of these in books and magazines before, and they are usually designed to give you a few hook-locations to build off of. I am working on some of the 8X8's and it not only seems guesswork from the start, but too often my guesses are damn near right without any effort. Are these well crafted puzzles? Do they multiple answers? What am I missing?...