(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 | |
|---|---|---|---|
 | Prismarine [Akari RGB] by wisty (on 16. October 2023, 09:10) | 18 |  96 % |
| One Of Two by Manta-Ray (on 18. November 2024, 15:36) | 16 | 91 % |
| Scorpion by IcyFruit (on 31. January 2025, 14:18) | 33 | 91 % |
| Skycagers (Build Your Own Killer Sudoku) by Agent (on 17. January 2023, 09:00) | 75 | 99 % |
| Little Killer Arrow Sudoku by Phistomefel (on 2. March 2021, 11:50) | 66 | 98 % |
| Sudokoban by DiMono (on 19. January 2023, 16:35) | 64 | 96 % |
| Doubler Chaos (Chaos Construction) by Mad-Tyas (on 19. November 2024, 23:39) | 117 | 96 % |
| Hochhäuser mit Kellern, Teil 3 by pirx (on 3. July 2015, 18:00) | 34 | 99 % |
| Chicago by ICHTUES (on 29. August 2021, 06:00) | 36 | 98 % |
| Jörmungandr by Jay Dyer (on 2. June 2022, 13:46) | 143 | 99 % |
| Fat X Little Killer Sudoku by Aspartagcus (on 31. August 2020, 10:20) | 29 | 96 % |
| Japanese Ranking by KNT (on 11. June 2024, 21:18) | 54 | 99 % |
| Onion by the_cogito (on 7. November 2023, 17:10) | 74 | 97 % |
| Unsichtbar Hochhauschaos by Luigi (on 22. November 2010, 12:54) | 36 | 95 % |
| Unique by TotallyNormalCat (on 5. February 2021, 01:30) | 45 | 98 % |
| Broken Gift (Partial Irregular Killer Sudoku) by peterchayward (on 16. May 2021, 11:42) | 39 | 92 % |
| CC: Red by lerroyy (on 2. August 2022, 23:07) | 18 | 91 % |
| Red Bubbles by antiknight (on 12. April 2023, 22:35) | 22 | 91 % |
| Chaos Construction: Exclusions by KNT (on 1. May 2024, 18:08) | 126 | 93 % |
| Neural Network by Xenonetix (on 26. November 2022, 14:41) | 37 | 95 % |
