(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 | |
|---|---|---|---|
 | Abstract Art by marty_sears (on 30. November 2023, 02:23) | 54 |  95 % |
| Lattice by pieguy (on 26. January 2023, 18:43) | 66 | 98 % |
| Min-Max-Sichtblöcke (4) by BFaw (on 14. December 2016, 10:00) | 20 | 94 % |
| Odd River - Prime Whispers Sudoku by ibn Muhyiddin (on 20. July 2020, 14:43) | 20 | 99 % |
| Gordian Knot by Joseph nehme (on 3. March 2021, 16:20) | 55 | 97 % |
| Mercury Arrows (Thermo Arrow) by tallcat (on 23. May 2021, 23:22) | 31 | 94 % |
| Doppelt (Double Arrow) by tallcat (on 17. September 2021, 16:48) | 38 | 97 % |
| Stairway to Heaven (collaboration with purpl) by TheRiddler (on 15. October 2021, 17:54) | 26 | 97 % |
| X-Sum Clues in the Grid by kolot (on 8. November 2021, 05:19) | 22 | 96 % |
| Confusing the Polarity by Allagem (on 20. May 2023, 08:31) | 21 | 96 % |
| Mayan Ruins (Run-on Renban) by riffclown (on 20. November 2023, 13:18) | 33 | 93 % |
| Smoke and Mirrors by gdc (on 22. February 2024, 20:05) | 41 | 91 % |
| Suguru Chaos Deconstruction: Quadruples by Niverio (on 3. May 2022, 12:39) | 89 | 98 % |
| Neue Post vom Außerirdischen by ibag (on 6. September 2015, 00:00) | 61 | 100 % |
| Exclusion (Thermo Renban Sudoku) by Phistomefel (on 27. March 2023, 18:43) | 126 | 98 % |
| The Ultimate Prime Cages by Xenonetix (on 11. June 2024, 23:45) | 94 | 97 % |
| Five Arrows (Entropy) by Mad-Tyas (on 24. October 2023, 12:48) | 60 | 93 % |
| Adamas by Polycarp (on 21. March 2021, 02:30) | 25 | 92 % |
| Cagey Royalty by Jagga (on 11. August 2022, 21:43) | 25 | 99 % |
| Bolts by antiknight (on 28. March 2023, 14:49) | 27 | 96 % |
