(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 | |
|---|---|---|---|
 | Chaos Construction with Slitherlink clues #2 by Phistomefel (on 21. September 2020, 19:41) | 70 |  98 % |
| 4D Arrow Sudoku by FryTheGuy (on 6. July 2021, 11:20) | 16 | 98 % |
| Chaotic Skyscraper Sums by Florian Wortmann (on 6. August 2022, 16:04) | 85 | 99 % |
| Ein Geburtstagsgruß von Wachtel, Wechtel, Wochtel und Wuchtel by ibag (on 27. March 2023, 20:00) | 14 | 98 % |
| BYO Arrows by Celery (on 28. October 2023, 22:44) | 38 | 91 % |
| Build Your Own Nuri-Maze #3: Crossing Slitherlink by Myxo (on 22. February 2024, 14:43) | 19 | 96 % |
| Sum Line Sudoku #2 by Phistomefel (on 8. October 2022, 12:57) | 113 | 98 % |
| Adventsportale, Teil 4 by pirx (on 23. December 2018, 12:00) | 47 | 96 % |
| Network by Niverio (on 15. February 2023, 16:20) | 73 | 97 % |
| Suguru Chaos Deconstruction #5: Region Sums by mathpesto (on 23. March 2022, 01:51) | 109 | 98 % |
| String Theory (Renban Incomplete Arrow) by tallcat (on 19. July 2021, 17:03) | 27 | 96 % |
| Crypto Japanese Cave-Bahn by KNT (on 18. January 2023, 07:32) | 51 | 98 % |
| Entropy Exhibition by Mad-Tyas (on 19. September 2023, 12:15) | 53 | 93 % |
| Shuttle islands [Nurikabe U-Bahn Bridges 13x14] by Christounet (on 16. January 2024, 01:00) | 26 | 96 % |
| Round totals reclining stucco deconstruction. (8, 7) by Oddlyeven (on 7. February 2024, 18:32) | 29 | 98 % |
| Zodiac Project: the year of the dög by aqjhs (on 20. November 2025, 00:55) | 25 | 98 % |
| Oklahoma City by ICHTUES (on 27. November 2022, 06:00) | 67 | 96 % |
| Knapp Daneben Twin Killer Sudoku by Richard (on 24. April 2009, 10:56) | 81 | 94 % |
| Top Right Boi by DubiousMobius (on 21. June 2025, 12:00) | 63 | 100 % |
| Pitchfork Emporium by FryTheGuy (on 21. December 2021, 04:10) | 31 | 95 % |
