(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 | |
|---|---|---|---|
 | Copycat Copycat by Scojo (on 24. June 2023, 04:05) | 15 |  100 % |
| Double Killer Sudoku by clover (on 15. December 2023, 21:57) | 33 | 99 % |
| Mount Elbrus (Killer sudoku with doublers) by Qodec (on 4. February 2024, 17:22) | 124 | 97 % |
| Parity Party XXIX, "Psy Ops" by glum_hippo (on 3. April 2024, 00:38) | 15 | 95 % |
| Dancing Like Butterfly Wings by dennischen (on 31. December 2024, 02:28) | 41 | 96 % |
| Regional Chaos by arbitrary (on 11. January 2025, 19:00) | 17 | 93 % |
| Los Angeles by ICHTUES (on 24. July 2022, 06:00) | 64 | 98 % |
| Japanische Höhle mit Irrwisch von den Außerirdischen by ibag (on 27. March 2018, 00:00) | 42 | 99 % |
| Five Dominos by Mad-Tyas (on 4. October 2022, 04:00) | 50 | 91 % |
| A kyler map [BYO Killer Deconstruction] by Christounet (on 16. October 2023, 18:29) | 29 | 97 % |
| The Fifteenth Day of Christmas by cristophermoore (on 18. December 2022, 07:01) | 48 | 98 % |
| A Powerful Duo (Entropy, Anti-Knight) by Mad-Tyas (on 16. May 2023, 09:08) | 46 | 94 % |
| Friendly Indexing Miracle by thoughtbyte (on 5. June 2023, 18:29) | 42 | 95 % |
| Knight's Whirlpool by SudokuExplorer (on 10. February 2022, 00:30) | 103 | 98 % |
| Wichtel 2019 (5): Japanische Pentominoplätzchen by wichtel (on 25. August 2020, 05:01) | 34 | 99 % |
| Puffer Fish by Qodec (on 28. November 2020, 22:05) | 44 | 98 % |
| Sandwich Fillomino #1 - Vicious Circle by Mark Sweep (on 19. March 2021, 10:00) | 14 | 98 % |
| Parity Party XIX, "Kryppto" by glum_hippo (on 10. June 2021, 17:06) | 25 | 100 % |
| Thonk? by purpl (on 3. May 2022, 00:26) | 26 | 95 % |
| Sprawl by jovi_al (on 22. September 2022, 20:27) | 24 | 95 % |
