(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 | |
|---|---|---|---|
 | Compass Sudoku by stephane.bura (on 25. December 2020, 00:00) | 45 |  99 % |
| Primality Party by abed hawila (on 12. March 2021, 15:44) | 13 | 96 % |
| XY-Differences and -Sums by glum_hippo (on 30. April 2021, 06:00) | 17 | 98 % |
| X-Box 180 by zegres (on 24. January 2022, 05:43) | 45 | 97 % |
| Knighten by Testarossa (on 24. January 2022, 21:37) | 81 | 95 % |
| The Andromeda Chain (Spiral Galaxies, Lockout Lines) by Chilly (on 8. February 2022, 16:08) | 13 | 98 % |
| Van Helsing by the_cogito (on 8. February 2022, 17:40) | 28 | 97 % |
| Faces by Pallando (on 11. March 2022, 11:53) | 22 | 100 % |
| Schrödinger's Leopard by tesseralis (on 12. July 2022, 11:52) | 42 | 99 % |
| Cliques by purpl (on 22. August 2022, 22:40) | 25 | 92 % |
| Robin Hood (Anti-king, Arrow Sudoku) by juddimal (on 2. September 2022, 23:39) | 33 | 91 % |
| Ringworms by XeonRisq (on 8. September 2022, 05:00) | 34 | 92 % |
| Self-determination 2 by stephane.bura (on 3. November 2022, 14:20) | 18 | 94 % |
| Under the Hill by Jay Dyer (on 16. January 2023, 22:51) | 53 | 96 % |
| Digital Sandwich by Prof.Dori (on 30. May 2023, 21:35) | 33 | 94 % |
| Don't be a smarTcaT ! by Christounet (on 19. June 2023, 17:48) | 33 | 98 % |
| Appaloosa by Die Hard (on 14. August 2023, 08:43) | 38 | 94 % |
| Alarm by zetamath (on 14. November 2023, 01:29) | 99 | 91 % |
| Sumthing by ThePedallingPianist (on 7. December 2023, 07:33) | 71 | 95 % |
| Dual U-Bahn by Paletron (on 12. April 2024, 20:45) | 27 | 99 % |
