(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 | |
|---|---|---|---|
 | Chaos by Nahileon (on 26. February 2022, 19:06) | 25 |  98 % |
| The Postman Problem by ThePedallingPianist (on 6. July 2023, 13:16) | 27 | 100 % |
| Vampires Magnet Butterfly by damasosos92 (on 15. April 2024, 16:40) | 28 | 93 % |
| Push and Pull by arbitrary (on 29. August 2024, 00:54) | 47 | 97 % |
| Fillomino Aquarium by Phistomefel (on 16. January 2022, 00:44) | 91 | 100 % |
| A Powerful Duo (Entropy, Anti-Knight) by Mad-Tyas (on 16. May 2023, 09:08) | 48 | 95 % |
| Product Sum Yin Yang by Scojo (on 17. June 2025, 04:10) | 42 | 93 % |
| Flat Cosmos (Chaos Construction) by sfushidahardy (on 13. August 2024, 23:53) | 82 | 99 % |
| Evil Eyes 4 v. 4 by Luigi (on 17. June 2010, 14:45) | 20 | 97 % |
| Wichtel 2019 (5): Japanische Pentominoplätzchen by wichtel (on 25. August 2020, 05:01) | 35 | 99 % |
| Interception (Arrow Sudoku) by tallcat (on 1. September 2021, 14:30) | 42 | 96 % |
| X-Sums killer sudoku #2 by udukos (on 10. October 2022, 21:08) | 63 | 98 % |
| Geometry Experiment 2 by Jeet Sampat (on 5. March 2023, 14:25) | 24 | 91 % |
| Renban Non-con by yttrio (on 21. April 2023, 20:26) | 42 | 96 % |
| [159] Di-Again-y! by ThePedallingPianist (on 11. October 2023, 01:47) | 21 | 91 % |
| Build Your Own Nuri-Maze #2: Oddsweeper Square by Myxo (on 26. January 2024, 20:13) | 22 | 93 % |
| Mount Elbrus (Killer sudoku with doublers) by Qodec (on 4. February 2024, 17:22) | 131 | 97 % |
| Wichtels Rätselsommer 2024 (3): Diebische Wichtel by wichtel (on 17. August 2024, 20:23) | 21 | 99 % |
| Mounting Pressure (Between Lines) by Blashyrkh (on 3. September 2024, 11:57) | 43 | 96 % |
| Schrödinger's Pseudoku by starwarigami (on 27. February 2025, 19:37) | 22 | 90 % |
