(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 | |
|---|---|---|---|
 | 6 Arrows by Jeet Sampat (on 25. September 2022, 22:46) | 32 |  96 % |
| Japanische Summen mit Hochhauskern - gründlich daneben by ibag (on 27. March 2014, 00:00) | 56 | 100 % |
| Proximity (Renban/Antiknight) by dumediat (on 13. May 2023, 14:29) | 66 | 92 % |
| Aqres of Shikaku Country (9x9) by mathpesto (on 29. October 2022, 22:57) | 33 | 98 % |
| Zebediah Killgrave by starwarigami (on 24. November 2023, 10:01) | 69 | 94 % |
| Wichtel 2015 (6): MERRY CHRISTMAS! by wichtel (on 18. May 2016, 20:15) | 39 | 99 % |
| Detroit by ICHTUES (on 14. November 2021, 06:00) | 45 | 97 % |
| Chaos: Killer by lerroyy (on 11. April 2022, 20:42) | 46 | 97 % |
| MIA by zetamath (on 24. May 2022, 16:03) | 91 | 98 % |
| The Lonely White Dot by XeonRisq (on 14. December 2022, 21:00) | 50 | 96 % |
| Ancient Ruins (Fog, BYO Killer, Nurikabe) by lepton (on 6. February 2023, 16:24) | 60 | 97 % |
| Quem Dixere Chaos by mathpesto (on 9. February 2022, 05:06) | 54 | 96 % |
| Indexed Chaos by Jay Dyer (on 3. September 2022, 23:42) | 68 | 100 % |
| Induction (Nonconsecutive German Whispers Sudoku) by Phistomefel (on 14. June 2022, 09:05) | 119 | 96 % |
| Snake Sum Sudoku 5 by Quarterthru (on 11. July 2020, 20:00) | 23 | 98 % |
| Thermo Arrow Sudoku by clover (on 15. October 2020, 00:54) | 14 | 98 % |
| Nonconsecutive Killer Sudoku by spxtr (on 1. January 2021, 06:21) | 87 | 95 % |
| Pencil puzzle sudoku hybrid series #5 - Slitherlink killer sudoku by Aspartagcus (on 9. January 2021, 14:48) | 28 | 95 % |
| Sandwich Fillomino #1 - Vicious Circle by Mark Sweep (on 19. March 2021, 10:00) | 13 | 98 % |
| Parity Party XIX, "Kryppto" by glum_hippo (on 10. June 2021, 17:06) | 23 | 100 % |
