(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 | |
|---|---|---|---|
 | Donuts by Die Hard (on 26. October 2023, 03:30) | 33 |  100 % |
| overflow underway by aqjhs (on 9. January 2025, 05:05) | 29 | 91 % |
| Antimatter by zetamath (on 14. January 2022, 01:53) | 43 | 94 % |
| Wichtel 2017 (10): Luftige Flotte an Wolkenmousse in inversem Schneegestöber by wichtel (on 17. October 2018, 07:04) | 24 | 99 % |
| Exploded Compass Sudoku by stephane.bura (on 7. January 2021, 20:00) | 39 | 100 % |
| Operation Arrows by EliasKar (on 17. January 2021, 16:25) | 38 | 100 % |
| A Bridge Before the Rainbow by fritzdis (on 20. March 2021, 21:35) | 13 | 93 % |
| 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 % |
| Skycagers (Build Your Own Killer Sudoku) by Agent (on 17. January 2023, 09:00) | 83 | 99 % |
| A Narrow Region by PotatoHead21 (on 21. February 2023, 20:25) | 15 | 95 % |
| Unlucky Sevens by noswald (on 7. June 2023, 04:52) | 46 | 94 % |
| Eclipsed Whispers by Space_man (on 7. May 2024, 05:52) | 39 | 95 % |
| Cave / Directionless Yajilin Permaculture by Agent (on 21. August 2024, 09:00) | 40 | 97 % |
| Trail of Prometheus (Secret Satan) by Agent (on 14. January 2025, 09:00) | 23 | 95 % |
| Rotterdam by ThePedallingPianist (on 26. September 2025, 18:56) | 16 | 91 % |
| Wichtels Rätselherbst 2025 (3): Eine schwierige Zusammenarbeit by wichtel (on 13. October 2025, 20:25) | 12 | 100 % |
| Fairy Rings by Jay Dyer (on 1. January 2022, 20:17) | 54 | 98 % |
| Thermohaline (Nurikabe Thermo Sudoku) by Agent (on 11. October 2022, 09:00) | 44 | 99 % |
| Convergence by TotallyNormalCat (on 18. February 2021, 22:30) | 31 | 98 % |
