This was hard, but fun! One suggestion: make empty spaces visually distinct from filled spaces. Why? Because cell 73 in the tenth puzzle (today's) is small eno

This was hard, but fun! One suggestion: make empty spaces visually distinct from filled spaces. Why? Because cell 73 in the tenth puzzle (today's) is small enough that I completely overlooked it, and used faulty logic to deduce all but two spaces before I discovered it. I was ready to file a bug report! I'll meet you halfway— if you'll please consider my feature request, I'll go visit my optometrist. :D