(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 | |
|---|---|---|---|
 | Mystery Killer Triplets (Little Killer Sudoku) by SudokuExplorer (on 8. August 2020, 03:00) | 21 |  98 % |
| Cage Escape (Thermo Killer) by Stavros96 (on 23. February 2021, 10:44) | 46 | 97 % |
| Speaking to the Atmosphere by EliasKar (on 28. April 2021, 13:28) | 22 | 92 % |
| Little Killer Between Sudoku by SudokuExplorer (on 24. August 2021, 02:00) | 36 | 96 % |
| X-sums Chaos Construction by Lizzy01 (on 14. January 2022, 19:18) | 57 | 99 % |
| Thermo x-sums sudoku by Aspartagcus (on 21. January 2022, 08:04) | 22 | 97 % |
| Chaos Construction: X-Sums and Lines by KNT (on 2. April 2022, 19:42) | 85 | 98 % |
| Bittersweet Candies 2 - A Regular 6x6 Sudoku Pack by Playmaker6174 (on 3. July 2022, 20:07) | 20 | 94 % |
| Jaguar's Paw (irregular 6x6) by Samish (on 23. July 2022, 10:10) | 21 | 95 % |
| Unplugged by Xenonetix (on 7. August 2022, 02:02) | 55 | 95 % |
| Phoenix by ICHTUES (on 25. September 2022, 06:00) | 130 | 96 % |
| Adventskalender 2023, Türchen 6 - Japanischer Buchstabensalat by Zzzyxas (on 6. December 2023, 07:00) | 53 | 99 % |
| All the Same and Never 4 by Jrosas (on 17. May 2024, 19:14) | 19 | 91 % |
| Cage Growing by Visumation (on 21. October 2024, 15:44) | 60 | 96 % |
| Empty Circles by Qodec (on 20. October 2023, 17:32) | 78 | 95 % |
| Roller Coaster mit Extras 18 by Uhu (on 10. May 2020, 20:16) | 38 | 98 % |
| Vierter Pfeilchenstrauß by glum_hippo (on 4. November 2020, 15:53) | 45 | 99 % |
| Quadiagonal by Tyrgannus (on 29. May 2021, 21:19) | 43 | 91 % |
| Baba is Anti-Knight by FryTheGuy (on 16. October 2021, 21:36) | 38 | 98 % |
| A Symmetry by twototenth (on 1. November 2022, 08:00) | 78 | 98 % |
