(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 | |
|---|---|---|---|
 | X---V*9 by NurglesGift (on 7. September 2025, 15:02) | 71 |  94 % |
| Almost Satisfaction by Joseph nehme (on 12. February 2022, 07:15) | 27 | 97 % |
| Double Equals by josh_johnson (on 13. August 2022, 23:59) | 21 | 96 % |
| Extraterrestrial Japanese Sums by KNT (on 16. February 2023, 01:26) | 40 | 100 % |
| The Slightly Irregular Fire Engine by glum_hippo (on 19. February 2023, 05:51) | 24 | 94 % |
| Run For Cover by 99%Sneaky (on 6. June 2023, 23:47) | 26 | 90 % |
| Regional Yajilin Sudoku by Myxo (on 7. December 2024, 12:23) | 44 | 91 % |
| Addierter Neuner in Doppelpack by Richard (on 5. February 2010, 12:00) | 70 | 94 % |
| Runder Rundweg 4 by pwahs (on 8. August 2009, 17:26) | 44 | 95 % |
| Illithid by PulverizingPancake (on 15. September 2021, 05:53) | 60 | 97 % |
| Harmony by Playmaker6174 (on 3. June 2022, 17:30) | 46 | 97 % |
| Yin Yang Icebarn by Jay Dyer (on 28. September 2022, 00:06) | 47 | 99 % |
| Modular Mayhem by Toomas_ (on 15. December 2024, 21:57) | 47 | 93 % |
| Impetus by NicoD (on 29. August 2025, 05:30) | 51 | 94 % |
| Dotropy (Entropic sudoku with kropki pairs) by Qodec (on 14. May 2023, 17:30) | 74 | 96 % |
| Hiding Spots by Xendari (on 27. May 2023, 10:21) | 76 | 96 % |
| Multiplied Cages by RockyRoer (on 2. December 2021, 03:40) | 21 | 93 % |
| Killer XL by Jeet Sampat (on 20. February 2022, 08:33) | 30 | 96 % |
| Secrets of Entropy by Mad-Tyas (on 26. December 2022, 03:00) | 46 | 93 % |
| Alfonso and Lori by zetamath (on 26. March 2023, 15:51) | 80 | 95 % |
