(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 | |
|---|---|---|---|
 | Dandelion (Anti-Knight Thermo Sudoku) by Phistomefel (on 7. June 2022, 02:45) | 175 |  97 % |
| Circle of Stars (Renban Quadruples) by Tyrgannus (on 4. April 2023, 21:33) | 56 | 92 % |
| Denver by zetamath (on 7. April 2023, 16:37) | 103 | 98 % |
| Liescrapers by marty_sears (on 12. January 2025, 18:39) | 112 | 96 % |
| Killer Little Killer Sudoku by Willy Wonka (on 18. August 2020, 15:27) | 50 | 95 % |
| Extemporaneous by NicoD (on 4. September 2025, 05:30) | 53 | 97 % |
| Coelacanth by Kafkapharnaum (on 1. April 2023, 20:20) | 62 | 98 % |
| Japanisches Memory by ibag (on 26. September 2014, 20:37) | 48 | 99 % |
| A Fillomino for the Bees by mathpesto (on 13. June 2023, 19:53) | 49 | 95 % |
| Numbered Regions X-Sums (9x9 Chaos Construction) by ONeill (on 24. November 2022, 22:58) | 52 | 98 % |
| Roller Coaster mit Extras 10 by Uhu (on 28. September 2018, 20:57) | 52 | 97 % |
| Star Python 2 (Star Battle Snake Sudoku Hybrid) by peterchayward (on 16. March 2021, 18:56) | 57 | 99 % |
| X-clusivity by Jay Dyer (on 9. August 2023, 22:15) | 117 | 97 % |
| Ein echtes Schachsudoku by CJK (on 23. August 2021, 15:39) | 66 | 97 % |
| Quantum Entanglement by Scojo (on 6. January 2025, 06:26) | 60 | 96 % |
| Splash by Joseph nehme (on 17. November 2022, 10:18) | 62 | 93 % |
| Not All Who Wander Are Lost by Allagem (on 4. August 2025, 13:29) | 61 | 94 % |
| Ulte Nus Plura (Suguru Chaos Deconstruction) by crispy16 (on 2. May 2022, 15:57) | 63 | 99 % |
| Fillomino U-Bahn by KNT (on 1. May 2023, 23:28) | 62 | 100 % |
| Quilt by mnasti2 (on 17. May 2023, 14:45) | 65 | 96 % |
