(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 | |
|---|---|---|---|
 | 1590 by twototenth (on 8. February 2022, 08:00) | 33 |  96 % |
| String Quartet by IcyFruit (on 5. November 2023, 01:26) | 77 | 96 % |
| Anti-Knight X arrow by psninn (on 29. October 2024, 09:19) | 75 | 91 % |
| Summenbild mit Lücken by Calavera (on 1. September 2009, 02:51) | 69 | 96 % |
| Compass Sudoku by stephane.bura (on 16. July 2020, 14:54) | 25 | 98 % |
| Anti-Knight Little Killer Sudoku by udukos (on 28. August 2020, 05:29) | 52 | 96 % |
| Multi-grid Multi-variant Sudoku - Simon Is Dead! by DiMono (on 14. November 2020, 09:00) | 26 | 98 % |
| XY-Differences VI, "Delimited Edition" by glum_hippo (on 4. February 2021, 20:09) | 27 | 99 % |
| Serial Killers by starwarigami (on 10. April 2023, 06:44) | 96 | 96 % |
| Eiger (Killer sudoku) by Qodec (on 3. December 2023, 15:41) | 154 | 96 % |
| Wichtel 2017 (4): Drei Wichtel und 144 Häuser by wichtel (on 26. May 2018, 07:04) | 37 | 99 % |
| Crypto Japanese Cave from the Underworld by KNT (on 30. October 2022, 05:29) | 37 | 99 % |
| Knight of Chaos by Andrewsarchus (on 4. December 2024, 18:44) | 41 | 98 % |
| Doppelgangland (Double Arrow Doublers) by tallcat (on 8. September 2025, 00:00) | 37 | 93 % |
| The Red and the Black (Anti-King Arrow) by tallcat (on 18. October 2021, 15:41) | 53 | 92 % |
| Detroit by ICHTUES (on 14. November 2021, 06:00) | 51 | 96 % |
| Whispers + Arrows + Renban + Sudoku X by Jeet Sampat (on 14. December 2022, 13:15) | 57 | 96 % |
| Sprengungen im Hochhausviertel II by tuace (on 18. January 2015, 23:36) | 38 | 98 % |
| Wheel of Fortune by Qodec (on 4. September 2020, 13:34) | 32 | 95 % |
| Archers Defending the Castle by GBPack (on 9. May 2021, 06:41) | 54 | 98 % |
