(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 | |
|---|---|---|---|
 | Xycle by ICHTUES (on 4. September 2022, 06:00) | 13 |  90 % |
| The Digits Are Paid Actors by Lizzy01 (on 5. November 2022, 21:40) | 26 | 99 % |
| A Narrow Region by PotatoHead21 (on 21. February 2023, 20:25) | 15 | 95 % |
| Unlucky Sevens by noswald (on 7. June 2023, 04:52) | 47 | 94 % |
| The Usurper by KMD (on 15. April 2024, 02:09) | 57 | 97 % |
| Eclipsed Whispers by Space_man (on 7. May 2024, 05:52) | 39 | 95 % |
| Trail of Prometheus (Secret Satan) by Agent (on 14. January 2025, 09:00) | 24 | 95 % |
| Schrödinger Lines Pt.2 by Zanno (on 20. March 2025, 15:11) | 13 | 91 % |
| Wichtels Rätselherbst 2025 (3): Eine schwierige Zusammenarbeit by wichtel (on 13. October 2025, 20:25) | 12 | 100 % |
| Thermohaline (Nurikabe Thermo Sudoku) by Agent (on 11. October 2022, 09:00) | 44 | 99 % |
| Chaos Deconstruction: Position Sums by KNT (on 29. June 2022, 16:05) | 85 | 98 % |
| Convergence by TotallyNormalCat (on 18. February 2021, 22:30) | 31 | 98 % |
| Unboxing by mathpesto (on 11. May 2023, 05:11) | 69 | 97 % |
| Reef by zetamath (on 26. June 2023, 03:35) | 123 | 97 % |
| A Whole Bunch of Nonsense by Myxo (on 30. October 2023, 22:00) | 73 | 95 % |
| The Landmark of Entropia by Mad-Tyas (on 30. March 2024, 09:11) | 36 | 93 % |
| Chaos Incorporated by Kafkapharnaum (on 4. April 2025, 01:23) | 38 | 100 % |
| the compeationist by aqjhs (on 5. June 2025, 05:28) | 38 | 97 % |
| the arithmancer by aqjhs (on 25. August 2025, 01:36) | 38 | 97 % |
| Chaos FilloSudokumino: Deconstruction by MagnusJosefsson (on 19. January 2023, 16:12) | 78 | 98 % |
