Definitely not “easy”. I would say some are medium and some are quite difficult.

Most are medium.

EDIT: Most are medium because of the interface.
I think there is an extra challenge doing them on paper.
I haven't trued the sample as I am busy for the next few days

I also think the longer one has practiced on these puzzles the easier they become.
I am one of of a small number people who has done all the book puzzles. Some were very challenging.
I learned tricks, skills doing all of the books.
The two books that Killer Sudoku books improved my skill at doing the Friday's Difficult. KS puzzle.

Medium, except if interrupted, lose focus and make it difficult.

I've put a sample 15x15 at:

https://www.calcudoku.org/special_puzzl ... _15x15.pdf


Can people confirm that this one can be classed as "difficult" ?

Thanks Patrick

I now have 3 15x15 puzzles to solve. This one, yesterday’s extra puzzle and the 15 years puzzle, which I have been struggling with for the last week or so. I’ll have a look at this one after I’ve solved the other two.

at first glance : yep difficult

Tricky, at first glance.

Here's a sample patterned 10x10, it should be fairly difficult,
but it does look like there are many good starting points
(so maybe it's not that hard):

Again at a glance looks like there are some tricky areas, definitely looks like a fun puzzle

I agree with frederick's appreciation; having 5 6-cell cages it looks probably difficult, at first glance.