(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 | |
|---|---|---|---|
 | Under the Hill by Jay Dyer (on 16. January 2023, 22:51) | 48 |  97 % |
| Neapolitan by pieguy (on 19. June 2023, 18:16) | 50 | 95 % |
| Qaak (Quattroquadri/Anti-diagonal/Arrow/Killer) by dumediat (on 24. August 2024, 15:50) | 46 | 95 % |
| Long and Short Arrow Sudoku by clover (on 19. October 2020, 12:53) | 34 | 95 % |
| Pierced Cages by Mark Sweep (on 29. January 2021, 10:00) | 34 | 94 % |
| Hot or Pointy? by Niverio (on 12. September 2022, 17:31) | 65 | 99 % |
| 5K 5T by Joseph nehme (on 24. April 2021, 06:31) | 54 | 97 % |
| Quetzalcoatl by Tyrgannus (on 24. September 2021, 21:29) | 50 | 93 % |
| Battle With The Archers 26: Reunion (aka Unity II) by Playmaker6174 (on 7. January 2022, 09:17) | 51 | 97 % |
| Knighten by Testarossa (on 24. January 2022, 21:37) | 77 | 95 % |
| Region Sum Lines Sudoku by Qodec (on 14. January 2022, 20:20) | 113 | 97 % |
| Fare thee well, Miss Carousel by Phistomefel (on 12. July 2024, 17:38) | 116 | 98 % |
| Sudoku Variants Series (288) - Battlefield Sudoku by Richard (on 30. September 2020, 00:00) | 64 | 96 % |
| Sudoku Variants Series (306) - Square Crow Sudoku by Richard (on 3. February 2021, 00:00) | 61 | 95 % |
| U-Bahn 3 by Dandelo (on 31. January 2021, 18:59) | 38 | 95 % |
| 真笑Puzzles030--69Sandwich(4) - -Uncertain Double Sandwich by cdwg2000 (on 25. February 2021, 12:30) | 19 | 100 % |
| Sudoku Variants Series (318) - Thermometers - Removed Bulbs by Richard (on 28. April 2021, 00:00) | 61 | 94 % |
| The c(l)over-up by Sktx (on 6. July 2021, 12:29) | 24 | 91 % |
| The Fool's Windmill by Fool on Hill (on 15. August 2022, 18:46) | 21 | 95 % |
| Sick and Twisted Sandwiches by Andrewsarchus (on 10. January 2023, 04:15) | 17 | 98 % |
