(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 | |
|---|---|---|---|
 | 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 % |
| Unique Value Deconstruction by sfushidahardy (on 27. June 2024, 18:13) | 34 | 96 % |
| Penumbra (Shadow Sums Sudoku) by Feadoor (on 19. June 2025, 10:56) | 37 | 94 % |
 | Super Sudokoid Dark Inversion by The M (on 9. May 2026, 00:00) | 48 | 100 % |
| Norinori Killer Sudoku by SudokuExplorer (on 9. February 2021, 01:00) | 80 | 96 % |
| Charybdis by Gliperal (on 21. March 2021, 05:46) | 52 | 97 % |
| XV Sandwiches by RockyRoer (on 21. November 2020, 04:47) | 34 | 95 % |
| Build Your Own Aquarium by wooferzfg (on 5. February 2022, 16:54) | 37 | 99 % |
| Equilibrium by Mad-Tyas (on 1. November 2022, 09:41) | 68 | 98 % |
| Ring Loop by Prof.Dori (on 29. September 2024, 02:09) | 36 | 94 % |
| Leftovers by ThePedallingPianist (on 16. October 2025, 03:10) | 71 | 97 % |
| Fog of Chaos by lepton (on 26. February 2023, 18:09) | 198 | 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) | 39 | 98 % |
| Arrow Logic by PotatoHead21 (on 17. May 2021, 21:03) | 20 | 95 % |
| Irrwisch Sudoku: Sandwich by Gliperal (on 22. May 2023, 11:30) | 52 | 97 % |
| Vacancy (Chaos Construction) by thoughtbyte (on 28. August 2023, 06:30) | 75 | 96 % |
