(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 | |
|---|---|---|---|
 | The Bald Eagle by LKegel (on 6. February 2021, 11:42) | 33 |  91 % |
| Reversion to the Mean (Regression zur Mitte) by cristophermoore (on 20. March 2021, 23:24) | 16 | 93 % |
| (Sudoku) Consecutive Decomposition by stimim (on 24. April 2021, 17:38) | 14 | 95 % |
| Suburbs by grkles (on 29. July 2021, 03:00) | 23 | 94 % |
| The BremSter Thermo Conundrum by Zombie Hunter (on 16. September 2021, 00:25) | 17 | 93 % |
| Flikk Flakk by PetLov (on 12. December 2021, 14:29) | 14 | 91 % |
| It's all math! by tenaliraman (on 20. January 2022, 19:04) | 12 | 95 % |
| Dropped Kropkis by Dag H (on 27. May 2022, 10:49) | 13 | 90 % |
| A Quiet Place by Crusader175 (on 15. July 2022, 18:00) | 25 | 95 % |
| Code 9-12 (Sudoku31) by Sumanta(ANU) (on 18. July 2022, 15:39) | 31 | 92 % |
| The Average Sudoku 2 by Lyun Licuss (on 12. September 2022, 05:39) | 16 | 92 % |
| Quietly Walking the Paths by EPH (on 21. September 2022, 02:22) | 45 | 95 % |
| Jellyfish by Nordy (on 11. February 2023, 08:00) | 15 | 91 % |
| Extreme measures (Parity killer/little killer) by sujoyku (on 24. August 2023, 15:00) | 28 | 93 % |
| Spirality by Nordy (on 6. June 2024, 08:30) | 15 | 91 % |
| Liar Japanese Sums: 48 Hour Special by SamuPiano (on 12. August 2024, 15:44) | 13 | 95 % |
| Hex Masyu with Branching by kiwijam (on 26. April 2013, 04:39) | 61 | 96 % |
| Michael Palin by starwarigami (on 4. April 2022, 21:18) | 51 | 97 % |
| Shoot the Pears by tallcat (on 9. April 2021, 15:50) | 41 | 96 % |
| Symmetry? by Qodec (on 13. April 2021, 20:16) | 75 | 91 % |
