(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 | |
|---|---|---|---|
 | Rising Arrow Sudoku - Halloween Crab by DiMono (on 3. June 2021, 18:26) | 54 |  97 % |
| Deconstruction Chaos Suguru #1,729: It’s All a Lie! by mathpesto (on 2. April 2022, 20:58) | 123 | 99 % |
| Skyscraper^2 Sudoku by Prasanna16391 (on 5. August 2020, 13:47) | 25 | 99 % |
| Encaged Kropki #2 - oops! no cage totals! by RockyRoer (on 21. October 2020, 00:00) | 22 | 99 % |
| Recycler by Jay Dyer (on 24. March 2022, 19:39) | 24 | 99 % |
| Wichtel 2021 (10): Eine lange Reise by wichtel (on 8. November 2022, 02:12) | 19 | 99 % |
| C.C. Geass by lerroyy (on 8. August 2022, 04:00) | 46 | 99 % |
| Unendliches Höhlenrätsel (Infinity Cave) by Phistomefel (on 3. April 2023, 20:00) | 27 | 91 % |
| The third wheel by chameleon (on 13. October 2025, 13:19) | 26 | 92 % |
| Four Colour Theorem by Jay Dyer (on 19. March 2022, 13:12) | 120 | 97 % |
| Chaos Arrows by Sotehr (on 27. September 2024, 15:19) | 51 | 93 % |
| Adorable Fury by DiMono (on 5. October 2021, 17:30) | 22 | 94 % |
| Building Regions in Fog of War: Border Patrol 2 by Jeet Sampat (on 7. April 2024, 12:24) | 24 | 91 % |
| Redshift by ThePedallingPianist (on 6. September 2025, 22:05) | 24 | 98 % |
| Killer Shikoku by the_cogito (on 9. March 2022, 00:16) | 62 | 96 % |
| Everything in its Right Place by marty_sears (on 16. October 2023, 01:53) | 118 | 99 % |
| Cryptic Skyscrapers (Alphabet Soup) by emmettcito (on 21. March 2021, 00:30) | 38 | 98 % |
| arROw SudOkU rEduX by filuta (on 20. April 2021, 13:49) | 18 | 93 % |
| Y Are We Whispering? by glum_hippo (on 18. September 2021, 04:12) | 36 | 94 % |
| Stepwell by mormagli (on 14. May 2022, 07:17) | 20 | 93 % |
