(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 | |
|---|---|---|---|
 | Suguru Chaos Deconstruction #4: Renban + Japanese Sums by mathpesto (on 7. March 2022, 17:30) | 119 |  96 % |
| Spurious Skyscrapers by Yawnus (on 12. March 2023, 13:54) | 27 | 91 % |
| Japanese Sums #5: Disposition by Myxo (on 10. October 2023, 11:55) | 68 | 98 % |
| Arrow Sudoku by abed hawila (on 17. February 2021, 21:51) | 76 | 97 % |
| الشمس والقمر (ashshams walqamar) by mathpesto (on 31. March 2025, 07:17) | 43 | 99 % |
| Double or Nothing by jwsinclair (on 18. August 2025, 20:39) | 39 | 93 % |
| The Greatest Hits by juggler (on 20. October 2025, 11:31) | 42 | 92 % |
| F-Puzzle by PulverizingPancake (on 16. April 2021, 03:40) | 43 | 93 % |
| Portal Sum - Little Killer Sudoku by Playmaker6174 (on 22. April 2022, 16:46) | 22 | 96 % |
| Martytram Snake by Prof.Dori (on 6. June 2024, 15:38) | 21 | 91 % |
| Nestification Jigsaw 2 by Lyun Licuss (on 29. August 2024, 19:51) | 12 | 93 % |
| Red-Yellow-Green by Sumanta(ANU) (on 10. April 2025, 15:05) | 54 | 97 % |
| RGB by Qodec (on 11. September 2021, 14:17) | 85 | 97 % |
| Between Knights and Arrows by Phistomefel (on 21. February 2021, 12:22) | 125 | 95 % |
| Unresolved Differences by Scruffamudda (on 29. March 2023, 05:47) | 33 | 94 % |
| The Three Bears Sudoku by dance1211 (on 14. October 2020, 03:48) | 23 | 97 % |
| Tumbleweeds by djorr (on 6. September 2021, 14:00) | 20 | 97 % |
| Beacon Lighthouse (Chaos Construction - Phistomefel Tribute) by purpl (on 12. December 2021, 21:38) | 20 | 94 % |
| Between Friends by Die Hard (on 18. September 2023, 01:29) | 21 | 93 % |
| Masyup Kakuro by purpl (on 17. March 2024, 22:08) | 23 | 93 % |
