(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 | |
|---|---|---|---|
 | Sudoku Variants Series (279) - Parity Sections Sudoku by Richard (on 29. July 2020, 00:00) | 66 |  98 % |
| In Line by jwsinclair (on 14. August 2024, 17:45) | 62 | 95 % |
| Mystery Box by Jolly Rogers (on 18. October 2023, 11:57) | 65 | 97 % |
| Spaces in Between (Windoku Between Kropki X) by tallcat (on 8. May 2022, 17:17) | 75 | 96 % |
| Chinese Takeaway (Yin Yang Killer) by BenTen (on 3. May 2023, 23:51) | 143 | 97 % |
| 24 Rätsel in 24 Stunden (Teil 3) - Höhle by Zzzyxas (on 24. June 2017, 02:24) | 80 | 92 % |
| Fillomino-Yajilin-Tapa by CJK (on 4. April 2021, 21:15) | 102 | 100 % |
| Archaeology (Nonconsecutive arrow sudoku) by Qodec (on 4. September 2023, 13:45) | 103 | 95 % |
| So ein Durcheinander by Luigi (on 16. September 2009, 09:42) | 19 | 94 % |
| Ameisenstrasse by Luigi (on 6. May 2011, 12:16) | 21 | 93 % |
| Pentonimo Kakuro by julius64 (on 4. May 2013, 14:24) | 52 | 96 % |
| ROCK STAR - Buchstabenrätsel by DocLogic (on 5. February 2020, 19:28) | 37 | 91 % |
| Crypto Sandwich Sudoku - Easy as ABC by KeyserSoze (on 3. May 2020, 15:52) | 30 | 96 % |
| Heatmap Sudoku by Jesper (on 13. June 2020, 16:19) | 38 | 97 % |
| 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 % |
| 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 % |
| Poison Darts by LKegel (on 31. January 2021, 10:57) | 19 | 97 % |
| XV Thermo Sudoku by Quarterthru (on 28. February 2021, 12:00) | 66 | 91 % |
