(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 | |
|---|---|---|---|
 | A Lying Stars Mystery Killer by Djmelee3000 (on 24. September 2020, 21:07) | 29 |  98 % |
| Position Sums (Odd-even coded) by Realshaggy (on 5. February 2021, 12:00) | 42 | 98 % |
| Sudoku Variants Series (315) - Summing Up Sudoku by Richard (on 7. April 2021, 00:00) | 67 | 94 % |
| Multi-sudoku: Orb by DiMono (on 9. April 2021, 16:38) | 38 | 98 % |
| Shrek's Sums by twototenth (on 8. March 2022, 08:00) | 19 | 95 % |
| Wack by the_cogito (on 22. May 2022, 16:34) | 26 | 99 % |
| Regional Variants (ambiguous region sum lines) by AnalyticalNinja (on 4. June 2022, 02:54) | 34 | 98 % |
| Ye Olde Inn by Qodec (on 11. June 2022, 23:32) | 56 | 95 % |
| Fibonacci Fountain by Malrog (on 22. June 2022, 20:02) | 16 | 97 % |
| Shyscrapers by Lisztes (on 25. July 2022, 23:30) | 26 | 100 % |
| Cabo Verde by Qodec (on 3. October 2022, 20:17) | 100 | 98 % |
| Squeeze by JamesCullum (on 6. March 2023, 23:36) | 23 | 98 % |
| Skyscraper Thermos by dennischen (on 28. March 2023, 19:48) | 26 | 96 % |
| U-Bahn with Empty Clues (3) by KNT (on 27. July 2023, 04:46) | 57 | 99 % |
| Alarm by zetamath (on 14. November 2023, 01:29) | 88 | 91 % |
| Ice Cave by Agent (on 21. November 2023, 09:00) | 37 | 98 % |
| Landvermessung U-Bahn #1 by The Book Wyrm (on 4. April 2024, 21:40) | 25 | 97 % |
| Canal View Japanese Sums by Agent (on 28. May 2024, 09:00) | 41 | 98 % |
| Ominous Yajilin by Jay Dyer (on 23. June 2024, 21:12) | 46 | 96 % |
| Let It Go (Nurikabe/Skyscraper/Fortress) by MaizeGator (on 24. June 2024, 00:20) | 23 | 97 % |
