(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 | |
|---|---|---|---|
 | Ma'at's Transcript: Order from Chaos (Chaos Construction) by Chilly (on 13. July 2022, 13:07) | 95 |  100 % |
| Der verlorene Schlüssel by berni (on 5. March 2010, 14:34) | 51 | 98 % |
| Kropki Magnetplatten III by tuace (on 12. January 2014, 07:30) | 32 | 99 % |
| Alpträume by ibag (on 27. March 2017, 23:55) | 39 | 99 % |
| Roller Coaster mit Extras 11 by Uhu (on 11. October 2018, 18:15) | 54 | 97 % |
| Wichtel 2017 (12 und Schluss): Geteilte U-Bahn by wichtel (on 24. December 2018, 10:04) | 35 | 99 % |
| Fractional 10-in-9 killer sudoku by Nylimb (on 2. April 2020, 00:11) | 22 | 96 % |
| 4 Corners Killer Sudoku by Strosahl (on 30. September 2020, 17:20) | 35 | 94 % |
| Confetti Sums Killer Sudoku by Jesper (on 24. February 2021, 15:10) | 49 | 99 % |
| arROw SudOkU by filuta (on 1. March 2021, 18:08) | 29 | 91 % |
| Negatively Constrained Exploded Compass Sudoku by stephane.bura (on 8. March 2021, 09:00) | 20 | 94 % |
| Invisible Cages by Big Tiger (on 25. March 2021, 10:42) | 29 | 96 % |
| Little Killer by Strosahl (on 7. April 2021, 05:36) | 34 | 99 % |
| California skyscraper sudoku by Shinya (on 12. May 2021, 09:02) | 17 | 94 % |
| Palindrome Builder by Quarterthru (on 10. July 2021, 17:00) | 17 | 95 % |
| 4D Thermo Sudoku by FryTheGuy (on 27. July 2021, 17:13) | 15 | 94 % |
| Triple Decker by Mimaamakim (on 29. August 2021, 20:28) | 35 | 98 % |
| Houston by ICHTUES (on 5. September 2021, 06:00) | 26 | 92 % |
| Equal Sudoku by kolot (on 25. October 2021, 07:39) | 27 | 99 % |
| Anti-Knight, Arrows, and Renban by Jeet Sampat (on 26. October 2021, 23:26) | 39 | 94 % |
