(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 | |
|---|---|---|---|
 | Knapp Daneben Twin Killer Sudoku by Richard (on 24. April 2009, 10:56) | 75 |  94 % |
| Roman Whispers (XV German Whispers Sudoku) by Phistomefel (on 31. January 2022, 18:23) | 106 | 98 % |
| Odd Pentominoes on the Loose by JeffWajes (on 31. July 2022, 05:52) | 27 | 96 % |
| Utterly A Maze Thing by fjam (on 12. March 2023, 19:01) | 23 | 94 % |
| Chaos Construction: XY-Sums by ns08 (on 28. May 2023, 23:55) | 27 | 93 % |
| Saturn's Outermost Ring (Old Version) by loerting (on 15. December 2023, 13:28) | 30 | 94 % |
| Regional Scores by Big Tiger (on 16. December 2023, 13:45) | 27 | 99 % |
| Hurricane by SudokuExplorer (on 16. March 2021, 01:00) | 61 | 98 % |
| Chaos Construction: Numbered Rooms / Skyscraper / Sandwich Length by KNT (on 4. May 2022, 07:54) | 51 | 97 % |
| Exploded Compass Sudoku by stephane.bura (on 7. January 2021, 20:00) | 29 | 100 % |
| Hoverbike by tesseralis (on 10. July 2023, 04:47) | 32 | 98 % |
| Schrödinger 302: Schrödinger's Octopus by ViKingPrime (on 5. May 2024, 11:45) | 28 | 97 % |
| Order! Order! by IcyFruit (on 17. November 2023, 13:57) | 34 | 98 % |
| Parity Party XXII, "Party Hearty" by glum_hippo (on 4. January 2022, 04:19) | 39 | 98 % |
| Japanische Höhle mit Irrwisch von den Außerirdischen (2) by ibag (on 20. April 2018, 00:00) | 40 | 100 % |
| Mars Attacks! (2T1L CC) by Xenonetix (on 22. August 2022, 03:33) | 49 | 97 % |
| The Cross by Tom1i (on 15. December 2020, 15:06) | 55 | 99 % |
| Antimatter by Nahileon (on 19. December 2022, 21:19) | 53 | 96 % |
| Constructing a Murder Scene - Chaos Construction (Killer) by Mr.Menace (on 27. July 2022, 13:28) | 79 | 97 % |
| River Crossing by IcyFruit (on 22. February 2024, 14:37) | 75 | 98 % |
