(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 CaveSudoku by MagnusJosefsson (on 7. December 2022, 11:55) | 85 |  98 % |
| Enclosure by Xenonetix (on 21. September 2022, 01:11) | 43 | 100 % |
| Tachyons and Black Holes (Black Hole) by heliopolix (on 16. January 2023, 20:00) | 47 | 96 % |
| Zebediah Killgrave by starwarigami (on 24. November 2023, 10:01) | 77 | 95 % |
| Supernova by Nahileon (on 3. November 2021, 20:32) | 76 | 99 % |
| Shadow (Cave Skyscraper Hybrid) by tallcat (on 20. November 2022, 09:00) | 62 | 97 % |
| Chaos Construction: Slingshots by Piatato (on 26. January 2025, 00:45) | 74 | 97 % |
| Adventskalender 2020, Finale - Riesenrundweg by Zzzyxas (on 1. December 2020, 07:00) | 28 | 100 % |
| Ziemlich japanische Summen mit Irrwisch by ibag (on 10. June 2017, 10:00) | 27 | 99 % |
| Locust [Kropki Killer Sudoku] by Panthera (on 12. December 2020, 13:00) | 31 | 93 % |
| Atlantis by Kafkapharnaum (on 26. May 2023, 23:22) | 28 | 100 % |
| ✚ Whisper-me-Sum-thing Loop ✚ by ElChiglia (on 9. December 2023, 07:15) | 32 | 90 % |
| In Chaos there is Order by Ali M (on 15. March 2024, 21:55) | 31 | 92 % |
| Fifteen by Die Hard (on 20. March 2024, 00:27) | 26 | 98 % |
| Constance by lerroyy (on 17. May 2024, 11:20) | 29 | 100 % |
| N-Lines by Qodec (on 6. August 2025, 16:53) | 27 | 93 % |
| Rätselsuppe III by Luigi (on 30. June 2010, 08:04) | 78 | 97 % |
| Archers and Knights by SudokuExplorer (on 23. March 2021, 01:00) | 102 | 98 % |
| The Final Fourteen by FryTheGuy (on 20. October 2021, 05:38) | 29 | 96 % |
| Wordless Kakuro by qiuyanzhe (on 26. November 2021, 08:34) | 23 | 90 % |
