(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 | |
|---|---|---|---|
 | Little Irregular Killer 2 by Richard (on 29. August 2012, 12:00) | 74 |  94 % |
| Fortress at Midnight by Playmaker6174 (on 10. November 2021, 23:35) | 36 | 93 % |
| Loopy Parity X-Sums by yttrio (on 20. July 2024, 02:56) | 40 | 98 % |
| Siamese Rundweg Sudoku Twins by pokerke (on 2. December 2010, 21:35) | 49 | 96 % |
| Vivian by wooferzfg (on 4. September 2022, 19:13) | 55 | 96 % |
| Two-Zip by AFrayedKnot (on 8. October 2024, 08:34) | 57 | 96 % |
| Passing Storm (Antiknight Arrows) by Florian Wortmann (on 2. October 2022, 16:19) | 76 | 94 % |
| Jello by zetamath (on 1. October 2023, 15:25) | 87 | 93 % |
| 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 % |
| Sum Killer Between Us by XeonRisq (on 4. July 2022, 17:00) | 44 | 96 % |
| Whisper Dots by XeonRisq (on 24. September 2022, 20:00) | 12 | 93 % |
| All 14 by Mad-Tyas (on 19. October 2022, 11:39) | 54 | 95 % |
| Variations by Nebuzaradan (on 22. June 2023, 16:05) | 14 | 93 % |
| Icarus by Fool on Hill (on 24. August 2023, 20:47) | 51 | 93 % |
