(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 | |
|---|---|---|---|
 | Displacement (Arrow Sudoku) by Phistomefel (on 10. May 2022, 19:07) | 91 |  98 % |
| Chaos Construction: Position Sums (9x9) by Jesper (on 12. October 2021, 20:35) | 59 | 100 % |
| BYO Kropki Cages by mathpesto (on 10. December 2022, 02:33) | 67 | 99 % |
| Japanese Aquarium by Jay Dyer (on 3. January 2023, 23:06) | 58 | 99 % |
| Ready For Launch by Niverio (on 7. May 2024, 10:19) | 36 | 94 % |
| Colour Wheel (Colourful Killers, Rotational Pairs) by The Book Wyrm (on 18. May 2024, 00:55) | 31 | 94 % |
| Mounting Pressure (Between Lines) by Blashyrkh (on 3. September 2024, 11:57) | 32 | 95 % |
| Post Office Panic! by tesseralis (on 4. July 2022, 10:14) | 73 | 97 % |
| Killer Sudoku(003) by cdwg2000 (on 4. September 2020, 01:04) | 48 | 98 % |
| 10-in-9 Killer Sudoku by KNT (on 10. May 2022, 01:14) | 40 | 99 % |
| Pandora's Renban by JeffWajes (on 18. January 2023, 21:12) | 43 | 97 % |
| Tête-á-tête (Between Line Nabner) by tallcat (on 11. September 2023, 08:00) | 45 | 95 % |
| Polymorphic Chaos by thoughtbyte (on 22. August 2023, 13:53) | 66 | 97 % |
| Verrätselte Zahlenfolge by berni (on 30. March 2011, 21:27) | 31 | 97 % |
| Castle Wall/Cave #2 by MagnusJosefsson (on 28. May 2021, 10:02) | 29 | 98 % |
| The Devil's Arrow by PotatoHead21 (on 6. June 2021, 06:51) | 17 | 91 % |
| Suguru Chaos Deconstruction: Anti Equites by crispy16 (on 14. May 2022, 02:25) | 51 | 98 % |
| Shadow by TotallyNormalCat (on 4. July 2022, 14:00) | 37 | 97 % |
| Perforate by Xendari (on 14. July 2022, 08:22) | 34 | 97 % |
| Crypto Japanese Cave from the Underworld by KNT (on 30. October 2022, 05:29) | 34 | 99 % |
