(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 | |
|---|---|---|---|
 | Sæpenumerō by mathpesto (on 4. May 2022, 04:17) | 38 |  98 % |
| Fifth Floor Penthouses by SSG (on 8. July 2022, 07:32) | 22 | 91 % |
| 4's and 7's by the_cogito (on 26. July 2022, 21:20) | 20 | 92 % |
| All Things Being Equal by actinide (on 6. August 2022, 14:59) | 40 | 95 % |
| Maximum Security (Killer cages, Doublers) by AnalyticalNinja (on 8. February 2023, 21:15) | 40 | 96 % |
| Double U is actually an S by ademjaz (on 28. February 2023, 00:08) | 24 | 92 % |
| Nansuke Sudoku (formerly Word Search Sudoku) by ufdigga (on 13. April 2023, 23:21) | 19 | 97 % |
| XOR #2 by Blashyrkh (on 8. September 2023, 14:06) | 38 | 96 % |
| Ish-doku by ChinStrap (on 24. October 2025, 17:48) | 40 | 96 % |
| Angebranntes Kropki by Luigi (on 12. May 2011, 14:55) | 36 | 90 % |
| Moriarty Leaves A Clue by HalfBakedLunatic (on 19. August 2023, 23:43) | 52 | 93 % |
| Nightmare on Fillo Street by Jay Dyer (on 7. September 2023, 00:37) | 41 | 97 % |
| Zipper Galaxies by gdc (on 4. February 2024, 18:44) | 46 | 98 % |
| Donuts [Killer] by Malrog (on 8. October 2024, 00:55) | 47 | 94 % |
| Japanese Sums #4: Pinpoint by Myxo (on 5. October 2023, 10:49) | 63 | 99 % |
| Things in common by arbitrary (on 22. April 2024, 11:50) | 68 | 98 % |
| Hurra für Zafer! by Richard (on 30. August 2011, 00:00) | 59 | 96 % |
| Japanische Koralle 2358 by Uhu (on 30. December 2016, 19:00) | 57 | 98 % |
| Killer Sudoku - Sums or Products by udukos (on 2. November 2020, 20:26) | 42 | 96 % |
| Pencil puzzle sudoku hybrid series #3 - Aqre arrow sudoku by Aspartagcus (on 17. November 2020, 17:05) | 22 | 95 % |
