(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 | |
|---|---|---|---|
 | Stepping Stones by RockyRoer (on 2. October 2021, 15:00) | 30 |  98 % |
| 100 by EricRathbun (on 25. September 2022, 22:50) | 18 | 92 % |
| Réaltraí (Pentominous spiral galaxies/Fillomino) by dumediat (on 27. January 2024, 20:19) | 51 | 100 % |
| Total Chaos by Bert (on 5. June 2024, 18:32) | 31 | 98 % |
| Navigation by ThePedallingPianist (on 7. December 2024, 18:48) | 16 | 92 % |
| Norinori Killer Sudoku by SudokuExplorer (on 9. February 2021, 01:00) | 80 | 96 % |
| Liar Japanese Sums #3: Renban Square by Niverio (on 8. January 2023, 21:45) | 67 | 98 % |
| Charybdis by Gliperal (on 21. March 2021, 05:46) | 52 | 97 % |
| XV Sandwiches by RockyRoer (on 21. November 2020, 04:47) | 34 | 95 % |
| Sum Compass Sudoku by stephane.bura (on 31. December 2020, 20:00) | 33 | 100 % |
| Build Your Own Aquarium by wooferzfg (on 5. February 2022, 16:54) | 36 | 99 % |
| Ring Loop by Prof.Dori (on 29. September 2024, 02:09) | 33 | 94 % |
| Colossal Cave Sudoku by tesseralis (on 28. October 2022, 03:02) | 72 | 99 % |
| Fog of Chaos by lepton (on 26. February 2023, 18:09) | 192 | 92 % |
| Min-Max-Sichtblöcke (3) by BFaw (on 14. December 2016, 10:00) | 18 | 95 % |
| 159 Sandwiches by RockyRoer (on 19. February 2021, 21:33) | 35 | 99 % |
| Alley of Arrows by MavericksJD (on 19. April 2021, 13:36) | 38 | 98 % |
| Arrow Logic by PotatoHead21 (on 17. May 2021, 21:03) | 20 | 95 % |
| Vacancy (Chaos Construction) by thoughtbyte (on 28. August 2023, 06:30) | 74 | 96 % |
| The Deck of Many Things by ViKingPrime (on 7. September 2023, 20:30) | 18 | 98 % |
