(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 | |
|---|---|---|---|
 | Isolation by Nahileon (on 21. January 2022, 14:41) | 64 |  93 % |
| Swords by antiknight (on 5. April 2022, 20:45) | 46 | 94 % |
| Double Date [Doublers, Killer, Renban, Arrow collab with Tallcat] by Malrog (on 15. April 2024, 14:47) | 45 | 96 % |
| Whispering Windmill by Rab3aron (on 5. March 2026, 16:59) | 21 | 94 % |
| 7 8 9 by Lutterot (on 2. December 2025, 21:28) | 51 | 91 % |
| Cave Sums Sudoku by Christounet (on 2. January 2026, 20:39) | 47 | 99 % |
| Palindrome Madness by SirWoezel (on 2. June 2020, 18:26) | 26 | 92 % |
| District 9 by tesseralis (on 17. August 2022, 10:15) | 25 | 100 % |
| Prism Redux by SeaOtter417 (on 2. November 2022, 15:47) | 35 | 91 % |
| Northwest Wind by SXH (on 22. December 2024, 07:06) | 37 | 91 % |
| Vikavolt by tesseralis (on 14. September 2022, 05:41) | 37 | 94 % |
| Spooky Action at a Distance by cygne (on 4. January 2026, 08:04) | 47 | 97 % |
| el veloz murciélago hindú by aqjhs (on 6. November 2024, 18:12) | 54 | 92 % |
| Doppelter Rundweg by rob (on 25. June 2014, 11:05) | 51 | 99 % |
| Deconstruksum [Position Sums Deconstruction] by Christounet (on 26. February 2023, 13:39) | 53 | 100 % |
| Japanische Summen 2358 by Uhu (on 3. September 2017, 17:47) | 57 | 98 % |
| Dutch Baby - a Snake Egg Sudoku by glum_hippo (on 13. January 2024, 07:17) | 71 | 96 % |
| Chaos Construction: Battlefield by Jesper (on 16. December 2021, 13:25) | 70 | 100 % |
| X-Sums & Sandwiches by kolot (on 2. April 2022, 03:02) | 105 | 99 % |
| Sudoku Variants Series (290) - Product Ltd Sudoku by Richard (on 14. October 2020, 00:00) | 77 | 94 % |
