(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 | |
|---|---|---|---|
 | Sandwich Sudoku--肉夹馍(2) by cdwg2000 (on 12. November 2020, 07:11) | 25 |  90 % |
| Rotationally Symmetric Antiknight Arrows II by kolot (on 5. October 2021, 10:38) | 27 | 94 % |
| Set The Bar High by SimiC (on 7. January 2022, 10:20) | 24 | 99 % |
| PrimeChip by WhatsWrong (on 22. July 2023, 13:14) | 26 | 96 % |
| Overlap (Run-On Renbans) by Skunkworks (on 8. September 2022, 17:38) | 59 | 98 % |
| Sharing is Caring (Twist on Renban Sudoku) by purpl (on 30. March 2022, 00:57) | 34 | 97 % |
| Cross The Streams by Uhu (on 3. August 2024, 21:19) | 32 | 97 % |
| Killer Quiver by MrMercurial (on 4. December 2020, 05:20) | 58 | 91 % |
| Contiguous by grkles (on 21. May 2022, 13:07) | 56 | 92 % |
| Anti-killer Sudoku by JoJoMcFroYo (on 26. June 2020, 14:55) | 24 | 90 % |
| X-Parity by LKegel (on 19. February 2021, 17:31) | 22 | 96 % |
| The Mine by FKlauser (on 18. April 2021, 20:30) | 25 | 90 % |
| Crystal by Qodec (on 22. June 2021, 22:53) | 64 | 91 % |
| Hybridsudoku: Winterurlaub in Südtirol by glum_hippo (on 5. December 2021, 19:52) | 20 | 94 % |
| Déjà Vu [Irregular Variant Sudoku] by wisty (on 26. May 2022, 08:41) | 23 | 96 % |
| Four Sevens by ThePedallingPianist (on 8. December 2022, 19:53) | 27 | 91 % |
| Sum Amount of Trouble by Tyrgannus (on 20. August 2023, 00:08) | 91 | 95 % |
| Inviscid Vorticity by heliopolix (on 22. January 2024, 06:33) | 22 | 90 % |
| LM 2018 Countdown: Japanisches Summen-Masyu by Uhu (on 7. June 2018, 09:06) | 47 | 96 % |
| Pentomino Schleifen by Richard (on 8. October 2010, 12:00) | 47 | 92 % |
