(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 | |
|---|---|---|---|
 | Triple Decker (Between Sandwich) by tallcat (on 3. August 2022, 17:53) | 60 |  96 % |
| Kakuro-Suguru Chaos Construction by mathpesto (on 25. January 2023, 20:05) | 82 | 97 % |
| Circles and Thermos by stimim (on 9. September 2023, 19:28) | 113 | 96 % |
| Juggling with the Twins (Partial Killer) by SudokuExplorer (on 2. October 2020, 02:00) | 29 | 95 % |
| Skyscrapers Sum by abed hawila (on 25. January 2022, 13:00) | 49 | 94 % |
| Thermos and Cages by Jeet Sampat (on 7. March 2022, 04:31) | 30 | 96 % |
| Sum Hope (Sum Lines) by Chilly (on 26. April 2022, 11:23) | 49 | 97 % |
| Room Service by Xenonetix (on 9. October 2022, 02:02) | 25 | 93 % |
| 1918 by starwarigami (on 19. October 2023, 11:29) | 51 | 96 % |
| Galaxies Collide by Prof.Dori (on 3. April 2024, 15:31) | 75 | 98 % |
| Schlangen im Fillomino-Nest II by tuace (on 3. March 2017, 11:24) | 36 | 99 % |
| Ambiguity 2 by zetamath (on 13. April 2021, 02:44) | 42 | 94 % |
| As My Guitar Gently Sweeps by Andrewsarchus (on 22. December 2021, 08:42) | 36 | 95 % |
| X-Box 180 by zegres (on 24. January 2022, 05:43) | 40 | 96 % |
| Renmometers by Jeet Sampat (on 1. June 2022, 21:50) | 44 | 92 % |
| Levity by Emphyrio (on 29. October 2022, 09:51) | 47 | 94 % |
| Intergrowth (Psycho Look-and-Say/Entropic lines/Modular lines) collab with bellsita by dumediat (on 25. February 2023, 12:51) | 42 | 99 % |
| Knight Fever by apiyo (on 31. January 2021, 03:19) | 60 | 96 % |
| Chaos Construction: Sightlines by Jay Dyer (on 5. March 2022, 16:15) | 67 | 97 % |
| Prison Break by Myxo (on 9. July 2023, 11:51) | 96 | 97 % |
