(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 | |
|---|---|---|---|
 | Noobahn by filuta (on 27. May 2023, 18:35) | 10 |  98 % |
| Liar Japanese Sums #7 - Ciphered Nurikabe by Niverio (on 1. December 2023, 00:53) | 43 | 100 % |
| Times Square (CTC Secret Santa 2023) by alexc (on 11. March 2024, 01:34) | 11 | 95 % |
| Arrow/Group Sum Sudoku by ahaupt (on 10. July 2020, 21:53) | 67 | 99 % |
| Sandwich Sudoku by kolot (on 15. July 2021, 18:33) | 36 | 96 % |
| U-Bahn under Tripleblock for polar by KNT (on 1. January 2024, 08:23) | 31 | 97 % |
| Colossal Cave U-Bahn by Agent (on 29. April 2025, 09:00) | 36 | 100 % |
| Wichtel 2012 (1): Der verwirrte Weihnachtsmann by wichtel (on 18. March 2013, 21:30) | 41 | 99 % |
| Misfits by filuta (on 10. November 2022, 17:30) | 40 | 99 % |
| Cavino Wisteria by PrimeWeasel (on 9. November 2024, 09:48) | 25 | 100 % |
| Trail of Prometheus (Secret Satan) by Agent (on 14. January 2025, 09:00) | 20 | 100 % |
| Trapped by a Killer by SudokuExplorer (on 25. November 2021, 00:00) | 61 | 96 % |
| Triple Japasu IV - Pin7guins nightmare by Luigi (on 23. May 2018, 09:22) | 29 | 95 % |
| Mission Improbable by XeonRisq (on 5. August 2023, 17:00) | 29 | 98 % |
| Japanese Japanese Sums Sums #1 by The Book Wyrm (on 30. November 2023, 22:11) | 39 | 98 % |
| Subway To Hell by Piatato (on 27. January 2024, 15:45) | 32 | 100 % |
| Roller Coaster of Emotions by Agent (on 25. December 2024, 09:00) | 33 | 100 % |
| Four Alien Theorem (Build Your Own Killer Sudoku) by Agent (on 7. April 2023, 09:00) | 53 | 99 % |
| Sudokuvania: Digits of Despair (v1.1.1) by SkepticalMario (on 4. April 2025, 02:27) | 194 | 100 % |
| Liar Japanese Sums #5 - Ciphered Cave by Niverio (on 11. February 2023, 11:40) | 54 | 99 % |
