(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 | |
|---|---|---|---|
 | Tachyons and Black Holes (Black Hole) by heliopolix (on 16. January 2023, 20:00) | 41 |  95 % |
| Origin (Coordinate arrows/Negators) by dumediat (on 21. October 2023, 16:10) | 19 | 100 % |
| Some Octopus Somedoku by blackjackfitz (on 18. May 2024, 22:51) | 20 | 94 % |
| All-ternating by MonsieurTRISTE (on 13. August 2025, 10:38) | 18 | 97 % |
| Japanese Ranking by KNT (on 11. June 2024, 21:18) | 60 | 99 % |
| Philadelphia by ICHTUES (on 28. November 2021, 06:00) | 47 | 95 % |
| Product Sum Yin Yang by Scojo (on 17. June 2025, 04:10) | 39 | 93 % |
| Chasm Construction by AFrayedKnot (on 23. May 2024, 22:35) | 118 | 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 % |
| Copycat Copycat by Scojo (on 24. June 2023, 04:05) | 21 | 100 % |
| Stronghold by fjam (on 31. May 2024, 19:04) | 22 | 93 % |
| Try-ominos by damasosos92 (on 26. September 2024, 20:37) | 48 | 98 % |
| Fünf aßen Neun by MavericksJD (on 30. January 2022, 19:53) | 28 | 95 % |
| Quadratum by Xenonetix (on 23. July 2022, 22:22) | 50 | 99 % |
| Constance by lerroyy (on 17. May 2024, 11:20) | 28 | 100 % |
| Elementary by Christounet (on 18. September 2023, 22:30) | 53 | 98 % |
| Enlightningment (Sudokuvania boss) by SkepticalMario (on 30. May 2025, 07:00) | 63 | 92 % |
| Cave 20x20 by Strosahl (on 8. December 2020, 20:54) | 32 | 97 % |
