(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 | |
|---|---|---|---|
 | Nightmare on Fillo Street by Jay Dyer (on 7. September 2023, 00:37) | 35 |  97 % |
| XOR #2 by Blashyrkh (on 8. September 2023, 14:06) | 34 | 97 % |
| The Arkenstone by Blobz (on 11. November 2022, 16:00) | 37 | 99 % |
| Maximum Security (Killer cages, Doublers) by AnalyticalNinja (on 8. February 2023, 21:15) | 36 | 96 % |
| Hooked on Sudoku by Blashyrkh (on 18. June 2024, 10:42) | 82 | 93 % |
| Steamed 'Bans (chaos construction with region sum clues) by SkepticalMario (on 5. September 2024, 00:00) | 70 | 97 % |
| Cryptic Kropki Sudoku by Greg (on 25. July 2020, 22:01) | 38 | 98 % |
| Killer Sudoku - Sums or Products by udukos (on 2. November 2020, 20:26) | 39 | 96 % |
| Anti-7 Arrows by ademjaz (on 31. January 2024, 09:25) | 42 | 95 % |
| Zwei Rundwege by Calavera (on 30. July 2009, 15:14) | 75 | 98 % |
| Little Killer Sudoku by Realshaggy (on 17. November 2019, 17:28) | 43 | 93 % |
| Three Out of Four Ain't Bad by Big Tiger (on 12. July 2020, 22:00) | 36 | 94 % |
| Paintball battle by Joseph nehme (on 26. December 2020, 18:04) | 41 | 97 % |
| X-Repeat Fillomino by MagnusJosefsson (on 21. May 2021, 13:45) | 37 | 100 % |
| RPG - The Enigma Trio by Playmaker6174 (on 24. December 2021, 16:30) | 39 | 96 % |
| The Final Shot: Four Corners 4 (Renban Arrow X) by tallcat (on 7. January 2022, 04:45) | 40 | 95 % |
| Kropki Chaos by mathpesto (on 23. January 2022, 04:19) | 75 | 97 % |
| Pathological by arbitrary (on 7. June 2024, 12:52) | 39 | 91 % |
| Adventskalender 2018 (Teil 23) - Yajilin by Zzzyxas (on 23. December 2018, 07:00) | 75 | 94 % |
| Flaemmchen-Sudoku mit Einmischung der Außerirdischen by ibag (on 2. August 2013, 05:30) | 36 | 98 % |
