(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 | |
|---|---|---|---|
 | 10-in-9 calcudoku #1 by Nylimb (on 27. January 2020, 10:04) | 34 |  97 % |
| Crossbar by purpl (on 12. August 2021, 07:12) | 36 | 94 % |
| Louisville by ICHTUES (on 6. February 2022, 06:00) | 36 | 95 % |
| Seven High by Die Hard (on 1. September 2023, 05:54) | 42 | 92 % |
| ↻ Somedoku-Loop ↺ by ElChiglia (on 27. April 2024, 07:05) | 36 | 92 % |
| Octagon by Jolly Rogers (on 31. August 2025, 18:18) | 41 | 95 % |
| Little Killer X Sudoku by Phistomefel (on 25. April 2020, 08:15) | 83 | 94 % |
| EUROPA - Buchstabenpyramide / letter pyramid by DocLogic (on 17. July 2020, 17:07) | 34 | 96 % |
| Cross Stitching 101 (Equalines Sudoku) by Sktx (on 1. November 2022, 15:51) | 34 | 91 % |
| Skyscraper Slingshot Sudoku #2 by Piatato (on 1. March 2023, 23:49) | 32 | 99 % |
| Meander (Slitherlink/Japanese sums sudoku) by dumediat (on 11. August 2023, 12:25) | 35 | 93 % |
| TEQUILA - Buchstabenrätsel / Letter Puzzle by DocLogic (on 13. January 2024, 15:46) | 31 | 97 % |
| Handshake (Arrow Sudoku) by Niverio (on 15. July 2022, 01:08) | 105 | 98 % |
| Little Big Killer Sudoku (updated) by Shinya (on 16. June 2020, 08:00) | 37 | 98 % |
| Neighbor Feud by Piatato (on 29. May 2021, 15:58) | 35 | 95 % |
| Roller Coaster mit Extras 24 by Uhu (on 5. October 2021, 14:00) | 31 | 99 % |
| Chaotic Indexers by mathpesto (on 15. July 2022, 22:15) | 35 | 100 % |
| Two Rights and a Wrogn by SirWoezel (on 20. July 2022, 21:57) | 37 | 95 % |
| Bashful Cages by Ennead (on 30. November 2022, 21:21) | 32 | 93 % |
| Secret Pressure by Wuschel (on 13. March 2023, 18:53) | 38 | 91 % |
