(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 | |
|---|---|---|---|
 | Through Space and Time (Chaos Construction) by Agent (on 23. September 2025, 09:00) | 60 |  99 % |
| Thermohaline (Nurikabe Thermo Sudoku) by Agent (on 11. October 2022, 09:00) | 43 | 99 % |
| Unique by TotallyNormalCat (on 5. February 2021, 01:30) | 47 | 98 % |
| Cosmogony by Kafkapharnaum (on 25. March 2024, 17:31) | 45 | 98 % |
| Schrödinger 302: Schrödinger's Octopus by ViKingPrime (on 5. May 2024, 11:45) | 35 | 97 % |
| Roller Coaster mit Extras 26 by Uhu (on 10. January 2025, 07:56) | 34 | 100 % |
| X-sums Killer Sudoku by udukos (on 4. October 2020, 04:28) | 33 | 97 % |
| Sudon'tku by IsaacR (on 19. November 2021, 06:52) | 32 | 91 % |
| Ancient Tablet by Kafkapharnaum (on 25. July 2023, 15:51) | 33 | 100 % |
| Party chaos by Lizzy01 (on 27. June 2024, 21:43) | 33 | 99 % |
| Chaos Construction: Minesweeper by Phistomefel (on 29. March 2021, 13:28) | 97 | 98 % |
| Country Road Fillomino #1 (10x10) by Jesper (on 10. October 2022, 15:41) | 62 | 99 % |
| Crypto Japanese Slitherlink by KNT (on 12. November 2022, 22:43) | 59 | 98 % |
| Miami Zipper by Prof.Dori (on 4. February 2024, 16:05) | 61 | 93 % |
| Japanische Summen-Koralle Knapp Daneben by Uhu (on 16. January 2017, 21:18) | 49 | 98 % |
| Killer Sudoku(002) by cdwg2000 (on 26. August 2020, 08:14) | 28 | 96 % |
| Kill o' the Whisp by starwarigami (on 1. June 2022, 20:10) | 26 | 90 % |
| Wichtel 2021 (5): Fehlkommunikation by wichtel (on 12. August 2022, 20:21) | 24 | 99 % |
| blue lining white trenchcoat by aqjhs (on 19. May 2025, 00:24) | 31 | 95 % |
| a night in the city by aqjhs (on 27. October 2025, 00:49) | 27 | 95 % |
