(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 | |
|---|---|---|---|
 | The Colour out of Space (Advanced Black Hole) by heliopolix (on 31. March 2024, 22:23) | 15 |  92 % |
| The Unity of Opposites by ViKingPrime (on 19. May 2024, 00:45) | 32 | 91 % |
| Some Octopus Somedoku by blackjackfitz (on 18. May 2024, 22:51) | 19 | 94 % |
| Stronghold by fjam (on 31. May 2024, 19:04) | 21 | 93 % |
| Afar by Andrewsarchus (on 28. June 2024, 08:57) | 15 | 91 % |
| Push and Pull by arbitrary (on 29. August 2024, 00:54) | 42 | 97 % |
| Nine in the Afternoon by Neokart (on 9. September 2024, 13:00) | 15 | 94 % |
| Japanese Sums with Marked Cells (2) by KNT (on 13. February 2025, 22:30) | 17 | 100 % |
| Overflow by IcyFruit (on 10. November 2023, 16:27) | 83 | 96 % |
| Coordinated Killers by Samish (on 11. September 2022, 09:09) | 61 | 96 % |
| Supernova by Nahileon (on 3. November 2021, 20:32) | 66 | 99 % |
| Ei8teen by Joseph nehme (on 13. August 2022, 08:19) | 63 | 99 % |
| Hawaii (Spiral Galaxy Sudoku) by PjotrV (on 5. February 2022, 15:04) | 58 | 97 % |
| Chaos Construction: Region Sums by KNT (on 7. April 2022, 20:42) | 61 | 99 % |
| Third Degree by Die Hard (on 13. February 2024, 11:52) | 61 | 95 % |
| Tag 24 - Finale by CJK (on 20. February 2021, 14:48) | 45 | 97 % |
| Chaosandwich by grkles (on 11. April 2022, 19:24) | 79 | 100 % |
| Chaos CaveSudoku by MagnusJosefsson (on 7. December 2022, 11:55) | 75 | 98 % |
| Compass Fillomino #5: Large Ring by MagnusJosefsson (on 3. September 2021, 10:59) | 35 | 97 % |
| Frak by zetamath (on 20. February 2022, 21:09) | 66 | 98 % |
