(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 | |
|---|---|---|---|
 | 7 Boom (Yin Yang). by palpot (on 10. February 2024, 13:55) | 25 |  96 % |
| Convergence by dawsonjones2020 (on 13. September 2024, 16:23) | 48 | 96 % |
| Stolen Numerals XVII-5 by NurglesGift (on 16. January 2025, 16:48) | 84 | 95 % |
| 33 by arctan (on 11. February 2025, 06:21) | 24 | 96 % |
| Cherry Blossom by egubachu (on 25. March 2025, 13:37) | 44 | 99 % |
| Interference by psninn (on 7. April 2025, 14:28) | 48 | 93 % |
| Square of Squares by juggler (on 12. May 2025, 21:33) | 77 | 97 % |
| Exogenous by NicoD (on 11. September 2025, 05:30) | 25 | 97 % |
| Sudoku Variants Series (300) - Killer Skyscrapers Sudoku by Richard (on 22. December 2020, 22:00) | 109 | 97 % |
| Cage Growing by Visumation (on 21. October 2024, 15:44) | 66 | 97 % |
| Battle With The Archers 8 - The Climax: Odd Crossroad by Playmaker6174 (on 19. July 2021, 13:00) | 43 | 97 % |
| Setting the Scene by PjotrV (on 14. October 2021, 15:23) | 47 | 94 % |
| The King With The Arrow by Joseph nehme (on 22. January 2022, 08:12) | 47 | 93 % |
| Equal sum chaos by Testarossa (on 2. June 2022, 16:01) | 44 | 93 % |
| Regional Skyscrapers Fillomino by Agent (on 25. October 2022, 09:00) | 37 | 100 % |
| X-sums Chaos Construction by Lizzy01 (on 14. January 2022, 19:18) | 62 | 99 % |
| Sudoku Variants Series (449) - Zipper Lines ++ by Richard (on 7. November 2025, 06:00) | 66 | 91 % |
| Kropki Indicator Sudoku by udukos (on 4. December 2020, 14:02) | 23 | 97 % |
| Eleven Arrows by EliasKar (on 3. April 2021, 07:44) | 42 | 97 % |
| Arrow Galore by SudokuExplorer (on 13. July 2021, 19:15) | 41 | 96 % |
