(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 | |
|---|---|---|---|
 | Dyscalculia by Lorena (on 7. February 2025, 15:30) | 31 |  93 % |
| Minus-or-Plus by FischmitFahrrad (on 16. March 2025, 22:02) | 17 | 95 % |
| Akari Sums by Oripy (on 7. April 2025, 12:00) | 18 | 93 % |
| Déjà Vu by ndsurgenor (on 6. April 2025, 11:00) | 19 | 93 % |
| Discombobulation by NicoD (on 9. May 2025, 05:30) | 121 | 97 % |
| Dutch Flat Mates: Y-Sums by Crusader175 (on 18. June 2025, 08:36) | 54 | 94 % |
| Colorful symmetry by Adrian71 (on 29. August 2025, 18:01) | 16 | 94 % |
| Tebak (Squishdoku + Killer Cage) by Krisonium (on 23. January 2026, 05:53) | 24 | 94 % |
| Whispering Chaos by 72kchunshuai (on 1. February 2026, 12:00) | 60 | 93 % |
| The Queen of Hearts' Labyrinth by Kjupatrick (on 20. January 2026, 10:20) | 28 | 93 % |
| Sigil of Intervals by masetab (on 4. February 2026, 15:23) | 23 | 93 % |
| 3 Vs: Vary Very Verily by gadgetgreen (on 15. February 2026, 21:14) | 22 | 91 % |
| seven swans a-swimmin' by aqjhs (on 18. December 2024, 03:45) | 116 | 97 % |
| Black-dot Mamba by yttrio (on 10. November 2023, 20:55) | 104 | 98 % |
| LM 2016 - Leftover: Yajilin by lupo (on 15. July 2016, 20:16) | 70 | 93 % |
| Chaos 12 (Chaos Construction) by MaizeGator (on 19. May 2025, 03:30) | 76 | 98 % |
| Sudoku Variants Series (415) - Parity Poopers by Richard (on 14. March 2025, 12:00) | 71 | 96 % |
| Hungarian Tapa / Roller Coaster (1) by KNT (on 23. September 2022, 20:45) | 65 | 100 % |
| Suguru Chaos Deconstruction by mathpesto (on 12. February 2022, 23:45) | 198 | 99 % |
| Battlefield Sudoku by Realshaggy (on 31. May 2020, 13:08) | 61 | 96 % |
