(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 | |
|---|---|---|---|
 | Olympic Rings by Jobo (on 5. August 2024, 01:14) | 97 |  96 % |
| 2024 Chaotic X-Sums by Florian Wortmann (on 10. January 2024, 19:23) | 106 | 98 % |
| Regional Yajilin — 'Abandoned Factory' by PixelPlucker (on 17. January 2022, 06:43) | 25 | 96 % |
| Renber Whispan by Sktx (on 9. July 2023, 18:29) | 30 | 94 % |
| [My 100th puzzle] The Secret of 100 by Mad-Tyas (on 5. October 2023, 13:48) | 24 | 96 % |
| Productivity Killer by starwarigami (on 13. January 2024, 21:02) | 25 | 92 % |
| Funhouse by zegres (on 12. April 2023, 14:52) | 64 | 96 % |
| Twin Chaos Sudoku II by Richard (on 30. March 2012, 12:00) | 72 | 92 % |
| Sum 41 - Little Killer / Arrow Sudoku by Mr.Menace (on 6. March 2021, 09:37) | 32 | 96 % |
| Killer Arrows by abed hawila (on 4. February 2021, 22:39) | 44 | 96 % |
| Border Square Diagonals by Phistomefel (on 21. May 2024, 19:16) | 100 | 97 % |
| Fremde Notizen by berni (on 22. May 2011, 22:48) | 17 | 98 % |
| Doppelter Rundweg by rob (on 25. June 2014, 11:05) | 49 | 99 % |
| Whispering Arrows by antiknight (on 8. April 2022, 22:57) | 18 | 98 % |
| Irregular Whirlpool by jojo81gaming (on 6. May 2022, 15:33) | 51 | 94 % |
| Denominators by AnalyticalNinja (on 29. January 2024, 00:30) | 26 | 99 % |
| Trapped by mathpesto (on 25. August 2024, 05:18) | 32 | 91 % |
| Odd X-Sums by Realshaggy (on 25. December 2021, 05:00) | 50 | 96 % |
| Primesweeper Sudoku by SenatorGronk (on 23. June 2020, 01:30) | 35 | 92 % |
| 真笑Puzzles013--Chaos Construction--“庄子” 004 by cdwg2000 (on 9. January 2021, 05:05) | 30 | 99 % |
