(Very) Hard AND nice puzzles
The following list contains portal puzzles that have been rated as nice or very nice and that are difficult. These puzzles are recommended for experts - and allow some time to solve.
| Description | solved | Rating | |
|---|---|---|---|
 | Parity Runs #2: Killer by Madmahogany (on 6. June 2020, 14:42) | 43 |  93 % |
| Slingshot Sudoku - Return of the Invisible Killers by stephane.bura (on 13. August 2020, 20:00) | 16 | 95 % |
| Invisible Slingshot Killers and Silent Killers Sudoku by stephane.bura (on 22. August 2020, 10:44) | 16 | 98 % |
| Even Couples Killer Sudoku by Quarterthru (on 3. September 2020, 12:00) | 25 | 96 % |
| Yajikazu Sudoku by Madmahogany (on 9. September 2020, 14:21) | 49 | 96 % |
| Partial Killer I "Windmühle" by glum_hippo (on 18. September 2020, 18:15) | 84 | 96 % |
| Basket Case by cam (on 30. September 2020, 01:34) | 17 | 94 % |
| Prime sum snake sudoku by Nylimb (on 27. November 2020, 07:54) | 21 | 97 % |
| The Negative Diagonal by Lisztes (on 1. December 2020, 01:00) | 18 | 92 % |
| Sudoku Variants Series (303) - Assorted Sandwiches Sudoku by Richard (on 13. January 2021, 00:00) | 82 | 98 % |
| Little Parity Party Sudoku by MagnusJosefsson (on 21. March 2021, 00:32) | 21 | 96 % |
| Ultimate Mashup by Joseph nehme (on 3. April 2021, 09:31) | 37 | 97 % |
| Übungsrätsel LM-Quali 2021: Pentopia-Myopia II by lupo (on 13. April 2021, 20:21) | 22 | 97 % |
| Mystery Kropki Sudoku #2 by Cane_Puzzles (on 13. April 2021, 15:30) | 28 | 93 % |
| Parity Party Renban Sudoku ('Party Bot') by PixelPlucker (on 31. May 2021, 16:05) | 17 | 95 % |
| A Very Odd Killer by Niverio (on 9. June 2021, 17:55) | 58 | 99 % |
| The 13th Nightmare by Nahileon (on 25. August 2021, 19:08) | 37 | 90 % |
| Think Outside the Cage by cristophermoore (on 22. September 2021, 03:35) | 41 | 98 % |
| Kropki-Arrow Party by abed hawila (on 6. November 2021, 09:40) | 42 | 97 % |
| Battle With The Archers 22: Double Speculations by Playmaker6174 (on 26. November 2021, 10:06) | 24 | 93 % |
