(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 | |
|---|---|---|---|
 | Compass Sudoku by stephane.bura (on 25. December 2020, 00:00) | 36 |  100 % |
| 38 (HBD Zetamath!) by Qodec (on 9. January 2022, 14:14) | 33 | 95 % |
| Corner Prison by Prof.Dori (on 7. November 2023, 10:23) | 194 | 95 % |
| Life on 36 cells by Phistomefel (on 13. January 2021, 00:42) | 102 | 95 % |
| Sandwiched in Between by udukos (on 16. January 2021, 05:37) | 28 | 99 % |
| Killer Around the Corner by SudokuExplorer (on 20. April 2021, 01:00) | 61 | 96 % |
| 159² by Sktx (on 2. September 2021, 01:17) | 26 | 94 % |
| Alien Cube by Nahileon (on 23. March 2022, 17:36) | 32 | 96 % |
| Numbered Sandwich Counts by RockyRoer (on 2. August 2022, 13:57) | 33 | 96 % |
| The Cs by ademjaz (on 23. September 2022, 00:54) | 31 | 92 % |
| Lightning Crashes by XeonRisq (on 23. February 2023, 04:00) | 34 | 92 % |
| Ikpork? by SSG (on 28. February 2023, 07:15) | 30 | 94 % |
| Careful with that hook, Emmett ! [S-Cell Sudoku] by Christounet (on 1. March 2023, 15:12) | 62 | 95 % |
| Mystery Boxes by Sumanta(ANU) (on 21. September 2023, 15:45) | 30 | 90 % |
| Bubbles by alexc (on 20. March 2024, 03:30) | 30 | 92 % |
| Gegentakt by Myxo (on 27. July 2024, 11:33) | 91 | 97 % |
| Anti-Fortress Arrow Sudoku by Phistomefel (on 17. January 2021, 21:52) | 85 | 94 % |
| Chaos Circles (Updated) by SenatorGronk (on 10. October 2023, 19:54) | 114 | 97 % |
| Coloring Book #9: The Corridor by blackjackfitz (on 23. October 2024, 17:05) | 50 | 94 % |
| Spin City by Bremster (on 26. November 2022, 04:47) | 84 | 95 % |
