(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 | |
|---|---|---|---|
 | Japanische Summen mit Hochhauskern - gründlich daneben by ibag (on 27. March 2014, 00:00) | 58 |  100 % |
| Ei8teen by Joseph nehme (on 13. August 2022, 08:19) | 69 | 99 % |
| Doubler XL by thoughtbyte (on 6. September 2023, 00:07) | 63 | 98 % |
| Zum Geburtstag by Uhu (on 9. July 2017, 00:00) | 42 | 98 % |
| Chained Killer Sudoku by Shinya (on 12. January 2020, 23:22) | 44 | 93 % |
| Friendly Indexing Miracle by thoughtbyte (on 5. June 2023, 18:29) | 43 | 95 % |
| Schrodinger's Split Peas by SamuPiano (on 12. July 2024, 15:44) | 43 | 97 % |
| Knight's Whirlpool by SudokuExplorer (on 10. February 2022, 00:30) | 112 | 98 % |
| Colour Wheel (Colourful Killers, Rotational Pairs) by The Book Wyrm (on 18. May 2024, 00:55) | 35 | 95 % |
| Roundabouts by Black_Doom (on 27. July 2024, 19:36) | 36 | 93 % |
| Deconstruction: Region Sums by Jay Dyer (on 24. April 2022, 22:14) | 55 | 99 % |
| Purple Archery Arrows by antiknight (on 9. October 2022, 17:25) | 63 | 95 % |
| Century (Counting Circles + Numbered Rooms) by tallcat (on 29. May 2024, 08:00) | 59 | 98 % |
| Non-Consecutive Territories by masetab (on 9. December 2025, 14:21) | 103 | 95 % |
| Too hot to hoot! - A Thermo Palindrome Sudoku by Philipp Huber (on 18. August 2020, 19:39) | 27 | 98 % |
| Tilted Mirror - Palindrome Killer Sudoku by Tyrgannus (on 27. March 2021, 05:26) | 26 | 98 % |
| Wichtel 2020 (7): Ärger in der Wichtelwerkstatt by wichtel (on 15. September 2021, 20:20) | 22 | 100 % |
| Surround Set by PrimeWeasel (on 11. February 2022, 12:12) | 22 | 98 % |
| Even Lighting by Jay Dyer (on 15. February 2023, 23:02) | 66 | 97 % |
| Build Your Own Killer: Criminal Mind by Playmaker6174 (on 3. March 2022, 18:07) | 42 | 100 % |
