(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 | |
|---|---|---|---|
 | Japanese Products Sudoku by RockyRoer (on 6. November 2023, 12:00) | 43 |  96 % |
| Wall Sudoku by Phistomefel (on 22. December 2021, 23:59) | 102 | 99 % |
| Hidden Identity Killers by Fluster (on 3. May 2021, 19:35) | 39 | 97 % |
| Dislocation by Ali M (on 26. July 2023, 22:58) | 75 | 92 % |
| Vampires by grkles (on 22. October 2021, 02:12) | 43 | 98 % |
| Who’s the man in the mirror ? [9×9 mirrored digits] by Christounet (on 11. September 2023, 18:21) | 72 | 97 % |
| Post von den Außerirdischen by ibag (on 6. September 2014, 06:09) | 32 | 97 % |
| Japanisches Summen-Masyu by Uhu (on 20. June 2017, 17:56) | 48 | 99 % |
| First Hidden Skyscraper Sudoku (Full Odd) by Feadoor (on 11. February 2020, 15:42) | 41 | 97 % |
| Gaelic Knot by cam (on 27. September 2020, 20:08) | 14 | 93 % |
| Killer sudoku: Noughts and Crosses by Martijn (on 5. October 2020, 12:07) | 15 | 90 % |
| Die Bahn ist auch auf dem Zylinder pünktlich ... by ibag (on 17. February 2021, 23:58) | 10 | 98 % |
| Antimagnetschlange by ibag (on 27. March 2021, 00:00) | 12 | 95 % |
| Angler by Dandelo (on 27. July 2021, 22:20) | 11 | 95 % |
| Mixed Doubles by Scruffamudda (on 4. November 2021, 23:37) | 12 | 98 % |
| Earthworm City (Killer + Renban Sudoku) by Sktx (on 17. August 2022, 10:57) | 12 | 98 % |
| Yin Yang Vaults by Schwupel (on 1. September 2022, 22:19) | 49 | 97 % |
| Cyclone by antiknight (on 2. September 2022, 04:07) | 28 | 90 % |
| Equivocation by SSG (on 27. September 2022, 07:02) | 35 | 97 % |
| Position Sums Fillomino #3: Internal Clues by ONeill (on 26. October 2022, 12:59) | 24 | 100 % |
