Fun game: Sudoku Mood (free, no ads, no download)

[Pluvious]

This site must be someone's labor of love for the game.
My SO really loves it, and now she's got me hooked too lol

From the site:

Sudoku is a numbers puzzle. It does not require any math, though. In fact, if we replace numbers with letters, shapes, or even colors - the puzzle won't change.
...
We've carefully crafted all our Sudoku puzzles to ensure that each of them is interesting to solve, no matter what level of difficulty you prefer.
...
Sudoku Mood was designed with simplicity in mind. Our goal is to make sure that users will be able to fully enjoy our website right after they see it for the first time.

https://www.sudokumood.com/

[stopdiggin]

1. have to do at least a couple a day

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

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

[MacKasey]

2. Thank you

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

[Pluvious]

3. Not bad !

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).

[Morbius]

4. Medium toughness, 12:40.

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

[Morbius]

5. A little better.

9:34.

[Pluvious]

6. You're a natural !

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.