Everyone tells me, "Oh, it keeps your mind sharp .. !"

response generally something like, "well - tell me when it's working .. " "we can always hope .. "

I just did my first one in just over 11 minutes.

My first (Easy type) took just over 12, but got a lot of red misses along the way

The real challenge is avoiding the misses (and not be lazy).

I haven't done a Sudoku in a long time. I used to be pretty good at this; out of practice.

9:34.

Getting down to 9 minutes is pretty good

There are some settings you can change, which will impact the game,
such as showing the candidates or not.

Also the hint button helps teach you with the concepts behind each correct move.