(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 | |
|---|---|---|---|
 | Diagonal Spiral by antiknight (on 6. July 2022, 22:35) | 29 |  92 % |
| Coral Subway by wooferzfg (on 26. March 2023, 22:35) | 26 | 100 % |
| Crab Net (with Math Pesto) by Paletron (on 29. October 2024, 11:42) | 30 | 96 % |
| Wheel of Fortune (Entropy) by Mad-Tyas (on 26. September 2023, 12:52) | 74 | 96 % |
| Killer Turm by tuace (on 17. November 2013, 09:30) | 46 | 98 % |
| Sagitta (Anti-XV Arrow Sudoku) by Phistomefel (on 1. August 2022, 17:06) | 119 | 94 % |
| Questionable Chaos (Y-sums / Skyscrapers sums chaos construction) by Lizzy01 (on 30. May 2022, 11:59) | 18 | 95 % |
| Watchers Along the Cave by tesseralis (on 9. August 2022, 08:54) | 31 | 96 % |
| Equilibrium 2: The Rune by Mad-Tyas (on 13. December 2022, 09:42) | 32 | 94 % |
| Crossroads by Knickolas (on 3. April 2023, 13:12) | 29 | 97 % |
| Pumpkin Wizard by Lizzy01 (on 15. October 2023, 14:09) | 16 | 92 % |
| Landvermessung U-Bahn by KNT (on 27. June 2024, 01:47) | 15 | 100 % |
| Projections (Killer Parity) by tallcat (on 12. November 2022, 08:00) | 35 | 96 % |
| Chaos FilloSudokumino: Deconstruction by MagnusJosefsson (on 19. January 2023, 16:12) | 69 | 97 % |
| Balanced Ride (Roller Coaster/Cave) by Piatato (on 23. October 2023, 11:00) | 32 | 99 % |
| Keep Talking [And No One Explodes] by zetamath (on 27. December 2021, 20:54) | 91 | 98 % |
| Deconstruction: Region Sums by Jay Dyer (on 24. April 2022, 22:14) | 49 | 99 % |
| Antiknight Thermo Sudoku by PotatoHead21 (on 26. July 2023, 18:25) | 50 | 96 % |
| Wichtel 2018 (2): Schnorchelreise by wichtel (on 6. June 2019, 10:28) | 35 | 99 % |
| Hendiadyoin Sudoku by ICHTUES (on 17. October 2021, 06:00) | 21 | 94 % |
