(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 | |
|---|---|---|---|
 | Hangover by Realshaggy (on 13. February 2022, 17:03) | 42 |  97 % |
| Valiant Viper in the King's Garden (Chess Snake Sudoku) by Nordy (on 5. April 2022, 01:20) | 33 | 95 % |
| Cavernous Construction by GarlicBredFries (on 5. May 2022, 06:47) | 79 | 98 % |
| Chaos Construction: diagonals by Prutsbeest (on 23. May 2022, 07:00) | 34 | 97 % |
| Entropy Focus by Mad-Tyas (on 8. September 2022, 14:54) | 47 | 96 % |
| Full Quads by mormagli (on 7. October 2022, 16:52) | 25 | 97 % |
| Skyscraper Slingshot Sudoku by Piatato (on 2. February 2023, 21:43) | 41 | 100 % |
| Headcrab by Blashyrkh (on 25. February 2023, 23:17) | 21 | 96 % |
| Turbulence (Coordinate Arrows) by Sotehr (on 3. July 2025, 14:00) | 29 | 94 % |
| Serial Killers by starwarigami (on 10. April 2023, 06:44) | 97 | 96 % |
| Neighbors Sudoku by Gliperal (on 26. June 2022, 14:51) | 81 | 97 % |
| Different, But Still Wrogn by DiMono (on 3. June 2022, 23:39) | 81 | 97 % |
| Ginnels & Snickets (Between Skyscraper) by tallcat (on 29. September 2022, 19:22) | 57 | 98 % |
| Sum Compass Sudoku by stephane.bura (on 31. December 2020, 20:00) | 35 | 100 % |
| 1590 by twototenth (on 8. February 2022, 08:00) | 33 | 96 % |
| Anti-Knight X arrow by psninn (on 29. October 2024, 09:19) | 75 | 91 % |
| Summenbild mit Lücken by Calavera (on 1. September 2009, 02:51) | 69 | 96 % |
| Compass Sudoku by stephane.bura (on 16. July 2020, 14:54) | 25 | 98 % |
| Anti-Knight Little Killer Sudoku by udukos (on 28. August 2020, 05:29) | 52 | 96 % |
| Multi-grid Multi-variant Sudoku - Simon Is Dead! by DiMono (on 14. November 2020, 09:00) | 26 | 98 % |
