(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 | |
|---|---|---|---|
 | Rectangle Rodeo (Region Sum Lines) by Mad-Tyas (on 2. March 2022, 22:42) | 21 |  90 % |
| Building The Unknown 2 by Joseph nehme (on 29. April 2022, 16:49) | 15 | 93 % |
| Clone College by SSG (on 17. January 2023, 07:17) | 37 | 95 % |
| Chaos Construction: Oblivion by XeonRisq (on 26. January 2023, 06:00) | 16 | 97 % |
| (9x9) Chaos Construction: X-sums Doubled Limit by Playmaker6174 (on 16. March 2023, 04:14) | 57 | 96 % |
| Jumelage [RSL Renban Twin Sudokus] by Christounet (on 22. October 2024, 13:09) | 15 | 95 % |
| Shuriken by crispy16 (on 24. May 2022, 19:43) | 40 | 94 % |
| Moriarty Leaves A Clue by HalfBakedLunatic (on 19. August 2023, 23:43) | 44 | 93 % |
| Knapp daneben-Tapa by flooser (on 10. June 2009, 12:32) | 88 | 96 % |
| Teams Sudoku - Counts and Sums by stephane.bura (on 31. May 2020, 14:27) | 20 | 97 % |
| Akari Sudoku by Prasanna16391 (on 30. July 2020, 00:05) | 18 | 90 % |
| Pencil puzzle sudoku hybrid series #3 - Aqre arrow sudoku by Aspartagcus (on 17. November 2020, 17:05) | 20 | 96 % |
| Rounded Killer Sudoku by RockyRoer (on 7. January 2021, 00:00) | 18 | 90 % |
| Effective Field Theory by purpl (on 28. September 2021, 02:18) | 34 | 98 % |
| Ranked Top 9 Best Digits (Rank Sudoku) by purpl (on 22. March 2022, 21:59) | 18 | 97 % |
| Sæpenumerō by mathpesto (on 4. May 2022, 04:17) | 32 | 98 % |
| 4's and 7's by the_cogito (on 26. July 2022, 21:20) | 18 | 92 % |
| Quarrowdruples by Joseph nehme (on 19. August 2022, 17:32) | 22 | 90 % |
| Sisyphos Fillomino (10x10) by Jesper (on 14. November 2022, 15:00) | 34 | 100 % |
| Chaos Snakes by Dag H (on 31. March 2023, 03:35) | 20 | 90 % |
