(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 | |
|---|---|---|---|
 | LM 2023 Überbleibsel - Japanische Summen, schwierigere Version by Zzzyxas (on 8. July 2023, 20:23) | 59 |  96 % |
| One Sum Yin & Yang by Visumation (on 9. June 2025, 10:25) | 81 | 95 % |
| A Fistful of Circles (fillomino) by SkepticalMario (on 21. November 2024, 01:01) | 83 | 96 % |
| Up to N-urikabe by sujoyku (on 29. October 2025, 21:15) | 88 | 98 % |
| Archaeology (Nonconsecutive arrow sudoku) by Qodec (on 4. September 2023, 13:45) | 107 | 95 % |
| Chaos Construction: Gaps by KNT (on 29. March 2022, 07:47) | 107 | 92 % |
| So ein Durcheinander by Luigi (on 16. September 2009, 09:42) | 19 | 94 % |
| Crypto Sandwich Sudoku - Easy as ABC by KeyserSoze (on 3. May 2020, 15:52) | 30 | 96 % |
| Wichtel 2019 (8): Notfall in der Wichtelwerkstatt by wichtel (on 23. September 2020, 18:21) | 39 | 98 % |
| Spiral Galaxies / Bent Hashi by stefliew (on 23. August 2020, 18:20) | 16 | 94 % |
| Anti-Killer Sudoku #3 by JoJoMcFroYo (on 16. September 2020, 22:49) | 22 | 96 % |
| Down The Drain Arrow Sudoku by bram (on 18. September 2020, 21:40) | 44 | 95 % |
| Knightsjump Sudoku by Prutsbeest (on 21. November 2020, 21:29) | 13 | 90 % |
| Sandwich Pseudoku - 10 Donuts by DiMono (on 19. January 2021, 16:47) | 15 | 92 % |
| Distant Relations #1 by Big Tiger (on 25. January 2021, 10:00) | 21 | 94 % |
| Poison Darts by LKegel (on 31. January 2021, 10:57) | 19 | 97 % |
| XV Thermo Sudoku by Quarterthru (on 28. February 2021, 12:00) | 67 | 91 % |
| Only Little Killer Sudoku by ICHTUES (on 7. March 2021, 06:00) | 25 | 96 % |
| PatrickRuchti - Kryptosudoku 2.0 by Johannes Quack (on 27. March 2021, 09:23) | 12 | 95 % |
| 真笑Puzzles037--Chaos Construction-- “邹子”002 by cdwg2000 (on 2. April 2021, 15:51) | 23 | 94 % |
