(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 | |
|---|---|---|---|
 | Six-pack Linked Sudokus by Genomico (on 25. August 2020, 00:57) | 90 |  97 % |
| Japanischer Summen-Rundweg 2358 (2) by Uhu (on 31. October 2020, 11:16) | 45 | 99 % |
| Insight Out (Chaos Construction) by sfushidahardy (on 24. July 2024, 21:57) | 50 | 95 % |
| Loopki by Senor Dingdong (on 8. July 2009, 15:15) | 48 | 90 % |
| Japanisches Memory by ibag (on 26. September 2014, 20:37) | 46 | 99 % |
| Roller Coaster mit Extras 10 by Uhu (on 28. September 2018, 20:57) | 48 | 98 % |
| Teleportation Cycle Sum Sudoku by SudokuExplorer (on 6. April 2021, 01:00) | 49 | 100 % |
| Numbered Regions X-Sums (9x9 Chaos Construction) by ONeill (on 24. November 2022, 22:58) | 49 | 98 % |
| Fillomino U-Bahn by KNT (on 1. May 2023, 23:28) | 52 | 100 % |
| Border Square Sums by Phistomefel (on 15. March 2024, 05:49) | 110 | 98 % |
| X-clusivity by Jay Dyer (on 9. August 2023, 22:15) | 110 | 97 % |
| Star Python 2 (Star Battle Snake Sudoku Hybrid) by peterchayward (on 16. March 2021, 18:56) | 56 | 99 % |
| clover's expert math class by Qodec (on 13. July 2021, 23:09) | 52 | 99 % |
| Ulte Nus Plura (Suguru Chaos Deconstruction) by crispy16 (on 2. May 2022, 15:57) | 54 | 99 % |
| Xs and Os [Parity, Whispers, Palindromes] by Malrog (on 5. December 2022, 01:42) | 50 | 98 % |
| Ein echtes Schachsudoku by CJK (on 23. August 2021, 15:39) | 66 | 98 % |
| Quadrature by Jay Dyer (on 6. February 2023, 23:33) | 60 | 95 % |
| Pacify by SamuPiano (on 26. March 2024, 17:00) | 56 | 97 % |
| Splash by Joseph nehme (on 17. November 2022, 10:18) | 60 | 93 % |
| Round the Houses (Killer Loop) by tallcat (on 25. March 2023, 15:37) | 61 | 97 % |
