(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 | |
|---|---|---|---|
 | Distant Relations #1 by Big Tiger (on 25. January 2021, 10:00) | 23 |  95 % |
| A Year in the Making by Polycarp (on 20. February 2023, 01:19) | 30 | 90 % |
| Chessmates Sudoku by Genomico (on 30. November 2023, 23:54) | 29 | 91 % |
| Double Stacks by bboom (on 24. May 2025, 14:46) | 32 | 93 % |
| C. by ThePedallingPianist (on 30. November 2025, 16:30) | 28 | 93 % |
| Shapes without Shapes by zetamath (on 2. March 2021, 04:28) | 44 | 94 % |
| Arrow or Centipede? by EricRathbun (on 11. September 2022, 18:08) | 48 | 99 % |
| Vendetta by NicoD (on 14. December 2025, 05:30) | 43 | 97 % |
| Siamese Rundweg Sudoku Twins by pokerke (on 2. December 2010, 21:35) | 49 | 96 % |
| Cryptic Star Nurikabe by BenceJoful (on 24. September 2021, 09:19) | 50 | 100 % |
| Vivian by wooferzfg (on 4. September 2022, 19:13) | 55 | 96 % |
| Passing Storm (Antiknight Arrows) by Florian Wortmann (on 2. October 2022, 16:19) | 77 | 94 % |
| Little Irregular Killer 2 by Richard (on 29. August 2012, 12:00) | 77 | 94 % |
| Inselhafen, Teil 3 by pirx (on 20. September 2018, 18:00) | 26 | 98 % |
| My first Sudoku by Selsted (on 12. July 2020, 18:42) | 32 | 90 % |
| Gravity Sudoku by Cane_Puzzles (on 15. February 2021, 16:49) | 23 | 99 % |
| Wanderlust by 10feet (on 5. August 2021, 13:00) | 32 | 92 % |
| Medieval by UnnamedSorcerer (on 5. August 2021, 03:17) | 15 | 93 % |
| Fievel Goes West by jsmirob (on 30. April 2022, 10:19) | 13 | 95 % |
| Kropki'd calcudoku #2 by Nylimb (on 30. June 2022, 00:35) | 14 | 98 % |
