(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 | |
|---|---|---|---|
 | Balance of Power by Raumplaner (on 26. June 2022, 14:40) | 20 |  98 % |
| Curvedoku by chameleon (on 1. July 2022, 13:23) | 17 | 100 % |
| Archery Range by grkles (on 12. July 2022, 17:05) | 40 | 92 % |
| Balanced Sudoku by Nell Gwyn (on 6. August 2022, 04:03) | 13 | 94 % |
| -X Sums by JeremyDover (on 5. October 2022, 23:23) | 14 | 98 % |
| Fusion by Crusader175 (on 7. October 2022, 17:12) | 14 | 94 % |
| Vice Versa by ICHTUES (on 20. November 2022, 06:00) | 15 | 98 % |
| Islands 3: Another Archipelagic Discovery by SamuPiano (on 21. July 2023, 01:44) | 14 | 100 % |
| Diagonal Indexing #1 by EPH (on 5. August 2023, 02:41) | 20 | 93 % |
| Palenban (Renban+palindrome sudoku) by Qodec (on 11. September 2023, 20:28) | 70 | 94 % |
| 10:01 AM by CaptZebraCakes (on 10. November 2023, 00:30) | 63 | 96 % |
| SMOG - Buchstabenrätsel / Letter Puzzle by DocLogic (on 4. May 2024, 13:16) | 26 | 95 % |
| Omaha by zetamath (on 21. June 2024, 04:57) | 41 | 97 % |
| The Quiet Whispers Between Loops by Jolly Rogers (on 30. September 2024, 20:28) | 42 | 94 % |
| Inverted Killer by NurglesGift (on 17. October 2024, 19:01) | 46 | 92 % |
| The 3-Colour Theorem by starwarigami (on 10. February 2023, 19:54) | 100 | 96 % |
| 3 Linked Sudokus by JonaS2010 (on 12. May 2019, 17:24) | 70 | 94 % |
| Two Sides of a Domino by TotallyNormalCat (on 30. June 2021, 20:30) | 53 | 91 % |
| Kreuzzahlrätsel (4) by berni (on 21. October 2010, 11:57) | 41 | 92 % |
| Bernis Geburtstag - Japanische Summen auf Klein'scher Flasche by ibag (on 15. June 2013, 15:25) | 36 | 95 % |
