(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 | |
|---|---|---|---|
 | Quadratum by Xenonetix (on 23. July 2022, 22:22) | 53 |  99 % |
| Chasm Construction by AFrayedKnot (on 23. May 2024, 22:35) | 121 | 98 % |
| Wichtel 2018 (2): Schnorchelreise by wichtel (on 6. June 2019, 10:28) | 35 | 99 % |
| Die Kryptos - S04E03: Roller Coaster by tuace (on 21. January 2020, 08:06) | 55 | 99 % |
| . o T o . by Lisztes (on 30. June 2021, 01:00) | 20 | 92 % |
| Wichtel 2021 (7): In der Weihnachtsbäckerei by wichtel (on 4. October 2022, 21:02) | 17 | 100 % |
| My cup runneth over intensely by Fool on Hill (on 19. August 2022, 13:29) | 23 | 95 % |
| Benefactors by Andrewsarchus (on 10. September 2022, 07:31) | 18 | 98 % |
| Origin (Coordinate arrows/Negators) by dumediat (on 21. October 2023, 16:10) | 20 | 100 % |
| Some Octopus Somedoku by blackjackfitz (on 18. May 2024, 22:51) | 20 | 94 % |
| Enlightningment (Sudokuvania boss) by SkepticalMario (on 30. May 2025, 07:00) | 97 | 92 % |
| All-ternating by MonsieurTRISTE (on 13. August 2025, 10:38) | 20 | 97 % |
| Keep Talking [And No One Explodes] by zetamath (on 27. December 2021, 20:54) | 101 | 97 % |
| The Barrel (Arrow Sudoku) by tallcat (on 18. April 2021, 05:29) | 91 | 98 % |
| Shade Your Own Puzzle: YinYang vs Sudoku #1 by Playmaker6174 (on 20. August 2024, 19:00) | 62 | 97 % |
| Philadelphia by ICHTUES (on 28. November 2021, 06:00) | 47 | 95 % |
| Kodama by zetamath (on 20. January 2022, 04:32) | 45 | 98 % |
| Loses Kalenderblatt April 2020 by April (on 1. April 2020, 00:00) | 21 | 94 % |
| Supercell by tesseralis (on 14. June 2022, 23:37) | 23 | 90 % |
| Deep sea weirdity (Between lines sudoku) by Lizzy01 (on 15. June 2022, 22:38) | 26 | 97 % |
