(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 | |
|---|---|---|---|
 | Parity Party XIX, "Kryppto" by glum_hippo (on 10. June 2021, 17:06) | 29 |  100 % |
| Hendiadyoin Sudoku by ICHTUES (on 17. October 2021, 06:00) | 24 | 94 % |
| Four body problem by filuta (on 21. November 2021, 18:11) | 14 | 92 % |
| Exactly Eighty by krangune (on 23. January 2022, 17:08) | 52 | 97 % |
| Frak by zetamath (on 20. February 2022, 21:09) | 76 | 98 % |
| Chaos by Nahileon (on 26. February 2022, 19:06) | 26 | 98 % |
| Biagonal Bichael (Chaos Construction) by purpl (on 29. May 2022, 17:32) | 39 | 98 % |
| The Unlikely Duos - A 6-pack Linked Sudokus Puzzle by Playmaker6174 (on 8. June 2022, 01:50) | 26 | 99 % |
| Coordinated Killers by Samish (on 11. September 2022, 09:09) | 65 | 96 % |
| Hook, Line and Sinker by SenatorGronk (on 29. September 2022, 00:21) | 20 | 92 % |
| Projections (Killer Parity) by tallcat (on 12. November 2022, 08:00) | 40 | 96 % |
| Parity Party XXIV, "Fast Times" by glum_hippo (on 30. November 2022, 17:14) | 20 | 96 % |
| Menagerie by SSG (on 13. December 2022, 07:14) | 29 | 95 % |
| Time by lerroyy (on 13. January 2023, 19:26) | 20 | 92 % |
| Tachyons and Black Holes (Black Hole) by heliopolix (on 16. January 2023, 20:00) | 51 | 96 % |
| O'Position [Ciphered Position Sums Fillomino] by Christounet (on 30. April 2023, 22:51) | 22 | 99 % |
| Atlantis by Kafkapharnaum (on 26. May 2023, 23:22) | 30 | 100 % |
| Thinking in Circles by Mennoo_ (on 22. June 2023, 11:34) | 23 | 93 % |
| Impossible Objects by tesseralis (on 8. September 2023, 07:40) | 41 | 98 % |
| Matchaluck (A Meidjuluk N=15 Variant) by PrimeWeasel (on 11. October 2023, 11:41) | 30 | 100 % |
