Please note: there is a clear break-in for those in the know, that will make this a straightforward solve (hence I have given this 3 stars). If you don't know the secret (not that one, Simon - well, not just that one) then you will find this a bit more tricky (nearer 5 stars).
All cages sum to the given value, or the cage sum is a square number, with no repeated digits.
Only consecutive dots inside a cage are shown, and all these are present.
The Little Killer diagonals sum to the given value and may repeat digits.
Solve the puzzle online at F-Puzzles.
Solution code: Enter the digits from Row 4, followed by the digits from Column 8
on 30. June 2021, 10:58 by steelwool
Edit board to match the instructions!
on 28. June 2021, 13:20 by steelwool
Update puzzle, missing difference cell!
on 27. June 2021, 21:48 by XeonRisq
Nice puzzle, loved the cage total restraint for the unnumbered cages. And interesting use of the negative restraint on dots only in cages.
-- thanks, i am pleased you enjoyed it.