(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 | |
|---|---|---|---|
 | Mannlzeug: Neinerlaa by Pyrrhon (on 24. December 2009, 18:00) | 43 |  90 % |
| Little Antiking Killer by PrimeWeasel (on 10. November 2020, 15:58) | 23 | 97 % |
| ThermoXidil by fritzdis (on 17. March 2021, 04:48) | 46 | 93 % |
| 3D Tapa - Count to Five by athin (on 25. June 2021, 12:00) | 17 | 98 % |
| Qnight by tsc (on 23. October 2021, 10:13) | 46 | 97 % |
| Two Wheeler by gtkrouwel (on 29. October 2021, 12:29) | 26 | 94 % |
| Roadmap by vidarino (on 14. November 2021, 19:21) | 22 | 97 % |
| Just Arrows! by Jeet Sampat (on 23. January 2022, 00:41) | 21 | 96 % |
| Cyclic Generators by SirSchmoopy (on 9. August 2022, 22:17) | 22 | 91 % |
| Po-Boy by Sniglett (on 1. December 2023, 14:06) | 61 | 95 % |
| Polyrhythm (Mod-length Index Lines) by DubiousMobius (on 27. February 2025, 23:27) | 23 | 91 % |
| There's Sum-thing In The Shadows (with sujoyku) by ChinStrap (on 2. May 2025, 18:05) | 73 | 97 % |
| 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) | 63 | 97 % |
| Known Unknowns (159 killer) by Chilly (on 27. October 2021, 11:12) | 37 | 97 % |
| Compass Cave by MagnusJosefsson (on 14. January 2022, 08:26) | 31 | 100 % |
| Entropic Arena by Raumplaner (on 16. October 2022, 12:07) | 36 | 92 % |
| Adulthood by GarlicBredFries (on 5. March 2023, 05:42) | 34 | 95 % |
| Pune by MavericksJD (on 30. March 2023, 12:51) | 107 | 98 % |
