(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 | |
|---|---|---|---|
 | [Fog of War Series] 4. Labyrinth by AstralSky (on 3. November 2022, 15:51) | 55 |  91 % |
| Headcrab by Blashyrkh (on 25. February 2023, 23:17) | 21 | 96 % |
| Venn Diagram Loops by Prof.Dori (on 9. May 2024, 16:44) | 49 | 99 % |
| Two Truths and a Lie by zetamath (on 20. September 2021, 14:48) | 159 | 98 % |
| Neighbors Sudoku by Gliperal (on 26. June 2022, 14:51) | 81 | 97 % |
| Different, But Still Wrogn by DiMono (on 3. June 2022, 23:39) | 81 | 97 % |
| Eiger (Killer sudoku) by Qodec (on 3. December 2023, 15:41) | 149 | 96 % |
| Tête-á-tête (Between Line Nabner) by tallcat (on 11. September 2023, 08:00) | 52 | 95 % |
| Drainers and Sires by mathpesto (on 23. June 2025, 15:52) | 49 | 96 % |
| 1590 by twototenth (on 8. February 2022, 08:00) | 33 | 96 % |
| The Big One by IcyFruit (on 25. January 2024, 14:04) | 43 | 96 % |
| Yozzy by zetamath (on 6. May 2024, 02:28) | 40 | 96 % |
| Japanische Summen-Koralle 2358 by Uhu (on 27. December 2016, 14:23) | 54 | 98 % |
| Bafflement by Xenonetix (on 3. October 2022, 01:10) | 56 | 100 % |
| Chaos Sandwich by Bert (on 24. February 2024, 16:36) | 60 | 94 % |
| Anti-Knight X arrow by psninn (on 29. October 2024, 09:19) | 73 | 91 % |
| Anti-Knight Little Killer Sudoku by udukos (on 28. August 2020, 05:29) | 51 | 96 % |
| Wheel of Fortune by Qodec (on 4. September 2020, 13:34) | 26 | 95 % |
| Multi-grid Multi-variant Sudoku - Simon Is Dead! by DiMono (on 14. November 2020, 09:00) | 25 | 98 % |
| XY-Differences VI, "Delimited Edition" by glum_hippo (on 4. February 2021, 20:09) | 26 | 99 % |
