(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 | |
|---|---|---|---|
 | Prison Break by Myxo (on 9. July 2023, 11:51) | 110 |  98 % |
| Urban Renewal (11x11 deconstruction) by jwsinclair (on 24. May 2022, 21:25) | 59 | 97 % |
| The Thing by mathpesto (on 16. October 2022, 04:48) | 53 | 91 % |
| OutsideTheUsula by Palfly Kampling (on 4. July 2023, 01:47) | 53 | 91 % |
| 1918 by starwarigami (on 19. October 2023, 11:29) | 58 | 96 % |
| Squishdoku by Jay Dyer (on 21. November 2023, 00:36) | 110 | 95 % |
| Ten-ish by ChinStrap (on 29. December 2025, 14:10) | 57 | 98 % |
| Nine Lives by ThePedallingPianist (on 12. May 2025, 14:40) | 140 | 96 % |
| Chaotic X-Sums by Florian Wortmann (on 6. September 2023, 18:09) | 128 | 97 % |
| Kyushu by AFrayedKnot (on 9. November 2024, 07:52) | 66 | 99 % |
| Knighten by Testarossa (on 24. January 2022, 21:37) | 82 | 95 % |
| Alarm by zetamath (on 14. November 2023, 01:29) | 100 | 92 % |
| Whispers of Doom 3 by NurglesGift (on 15. November 2025, 11:27) | 123 | 98 % |
| Space settlement by NicoD (on 2. April 2026, 05:30) | 117 | 98 % |
| Milchstraße (Sektor 23C) by usp (on 5. November 2014, 00:00) | 40 | 95 % |
| Entwined Sandwiches Sudoku by matt383 (on 7. April 2020, 17:25) | 44 | 97 % |
| ZIRKUS - buntes Buchstabenrätsel / colorful letter puzzle by DocLogic (on 30. April 2020, 22:59) | 34 | 98 % |
| Skyscraper Aquarium Sudoku by Sam Knott (on 23. June 2020, 18:01) | 32 | 96 % |
| 10-in-9 CLXVI sudoku by Nylimb (on 21. October 2020, 20:10) | 15 | 94 % |
| Disjoint Killer Arrows by Joseph nehme (on 13. December 2020, 17:11) | 30 | 96 % |
