(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 | |
|---|---|---|---|
 | Thermo Miracle Sudoku by SudokuExplorer (on 7. July 2020, 18:05) | 91 |  90 % |
| Schrödinger 203: Quantum Tunnelling by ViKingPrime (on 30. September 2023, 00:30) | 52 | 97 % |
| LM 2018 Countdown: A 38 (1) by tuace (on 2. June 2018, 09:06) | 41 | 95 % |
| Inselhafen, Teil 3 by pirx (on 20. September 2018, 18:00) | 26 | 98 % |
| Forget What You Knew (Similar 3x3 Sudokus) by EliasKar (on 29. January 2021, 01:11) | 14 | 90 % |
| 25 by ICHTUES (on 26. February 2021, 12:26) | 31 | 98 % |
| Medieval by UnnamedSorcerer (on 5. August 2021, 03:17) | 14 | 93 % |
| Knuckle Sandwich by PrimeWeasel (on 31. January 2022, 10:07) | 12 | 91 % |
| American Whispers - purpl Collab by the_cogito (on 20. February 2022, 14:37) | 12 | 95 % |
| _234_678_ by twototenth (on 22. February 2022, 08:00) | 44 | 92 % |
| Kropki'd calcudoku #2 by Nylimb (on 30. June 2022, 00:35) | 14 | 98 % |
| Whisper Dots by XeonRisq (on 24. September 2022, 20:00) | 12 | 93 % |
| Three is a Crowd Sudoku #2 by Genomico (on 27. September 2022, 20:55) | 13 | 100 % |
| Patchwork by steelwool (on 11. October 2022, 18:00) | 27 | 93 % |
| Happy Halloween! (Shifted X-sums 3) by Lizzy01 (on 27. October 2022, 19:48) | 13 | 93 % |
| Variations by Nebuzaradan (on 22. June 2023, 16:05) | 13 | 93 % |
| Clapping on the 1 and 3 by cristophermoore (on 6. November 2023, 00:00) | 41 | 93 % |
| Cage Dive by Peter the Dog (on 11. December 2023, 22:41) | 11 | 95 % |
| Sphygmomanometer by ViKingPrime (on 15. January 2024, 17:00) | 14 | 95 % |
| Two Sums by CaptZebraCakes (on 26. January 2024, 20:57) | 40 | 96 % |
