(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 | |
|---|---|---|---|
 | Little Killer by abed hawila (on 18. January 2021, 12:55) | 21 |  94 % |
| Two Wheeler by gtkrouwel (on 29. October 2021, 12:29) | 25 | 94 % |
| Transfer by Emphyrio (on 15. March 2022, 03:06) | 41 | 96 % |
| Cyclic Generators by SirSchmoopy (on 9. August 2022, 22:17) | 22 | 91 % |
| Winded Arrows (Irregular Sudoku) by Aaronomys (on 22. August 2022, 05:18) | 19 | 99 % |
| Time Twister (Killer/Entropic Lines) by Tyrgannus (on 31. August 2022, 23:15) | 43 | 95 % |
| Lace Agate by Niverio (on 4. June 2023, 09:56) | 128 | 95 % |
| Extra Tall Skyscrapers by yttrio (on 4. August 2023, 20:04) | 40 | 97 % |
| All Truths, All Lies by dodomos (on 25. October 2023, 10:00) | 47 | 91 % |
| Roller Coaster by igniteice (on 29. November 2023, 05:58) | 23 | 91 % |
| Quantum Chaos (CC, S-Cells) by gdc (on 31. August 2024, 00:26) | 47 | 94 % |
| Sudoku Variants Series (033) - Little Killer by Richard (on 15. July 2014, 00:00) | 160 | 95 % |
| EXit Strategy by riffclown (on 17. May 2023, 13:35) | 92 | 93 % |
| 10-in-9 calcudoku #2 by Nylimb (on 14. March 2020, 14:49) | 32 | 97 % |
| Phistomefel-Tribute-Thermo-Sudoku by olima (on 19. July 2020, 03:39) | 39 | 92 % |
| Trail of Arrows by SudokuExplorer (on 25. January 2022, 18:30) | 61 | 96 % |
| Schlangennest — mal anders by glum_hippo (on 19. March 2022, 16:57) | 39 | 95 % |
| Adulthood by GarlicBredFries (on 5. March 2023, 05:42) | 33 | 95 % |
| Yin Yang Arrows by yttrio (on 13. October 2023, 23:06) | 110 | 98 % |
| U-Bahn unter Hochhäusern (Teil 4) by Zzzyxas (on 31. March 2012, 16:17) | 74 | 96 % |
