(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 | |
|---|---|---|---|
 | 100 Streams of Zetatude (renban, region sum, doublers) by Chilly (on 18. October 2022, 18:23) | 12 |  93 % |
| Snake Parents by lepton (on 21. January 2023, 07:25) | 12 | 95 % |
| Difference by mormagli (on 4. March 2023, 05:59) | 16 | 97 % |
| Friendly Indexers by thoughtbyte (on 1. June 2023, 06:18) | 11 | 93 % |
| Nurikabe Cousins by Agent (on 22. August 2023, 09:00) | 42 | 98 % |
| Nuts and Bolts the Sequel: Mowing the Lawn by KMD (on 26. March 2024, 00:13) | 12 | 98 % |
| Neural Network by Tobias Brixner (on 20. August 2024, 16:35) | 11 | 90 % |
| Chaos Construction: Disconnected (2) by KNT (on 20. May 2024, 04:09) | 82 |  100 % |
| Mystery Box by Nahileon (on 2. August 2022, 22:09) | 30 | 92 % |
| 4-Stern-Star-Battle by CJK (on 1. July 2021, 10:09) | 48 | 94 % |
| »Little Killer« unter Damen by glum_hippo (on 20. May 2020, 08:25) | 20 | 91 % |
| Three Rights and a Wrogn by SirWoezel (on 29. July 2022, 13:47) | 18 | 95 % |
| Stingray (Odd) - Numbered rooms+Parity lines Sudoku by Qodec (on 11. January 2023, 23:02) | 63 | 96 % |
| Entropy Sweeper by tesseralis (on 30. September 2023, 22:40) | 70 | 97 % |
| Nashville by ICHTUES (on 19. June 2022, 06:00) | 73 | 97 % |
| Buchstabenpaarreihen (4) by BFaw (on 30. March 2016, 11:00) | 36 | 97 % |
| Anti-Springer Killer, "Das Stundenglas" by glum_hippo (on 4. November 2020, 01:26) | 46 | 93 % |
| Scratches by PrimeWeasel (on 11. April 2021, 09:27) | 13 | 95 % |
| Black Eyes by Qodec (on 10. April 2022, 14:31) | 29 | 95 % |
| Mountain Aven by mormagli (on 2. October 2022, 04:37) | 14 | 90 % |
