(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 | |
|---|---|---|---|
 | Wichtel 2011 (10): Japanische Summen - knapp daneben by wichtel (on 7. March 2012, 10:00) | 81 |  97 % |
| Table for Four - Battleship by uvo (on 19. August 2014, 12:27) | 42 | 97 % |
| Kerzen 4 by usp (on 26. January 2015, 00:00) | 48 | 94 % |
| Chroma-Some (Killer) by zegres (on 5. March 2024, 05:31) | 49 | 91 % |
| A puzzle of two halves by arbitrary (on 13. April 2024, 11:32) | 89 | 98 % |
| Loopy Whisper X-Sums by yttrio (on 8. June 2024, 04:31) | 88 | 98 % |
| Secret Crossing by Groktilian (on 18. November 2024, 07:00) | 48 | 93 % |
| Lake Goldajärvi by EdTheAlchemist (on 26. December 2025, 13:58) | 49 | 97 % |
| Wichtel 2017 (6): Easy as Kakuro by wichtel (on 22. June 2018, 10:04) | 58 | 97 % |
| LITSomino by mathpesto (on 23. March 2024, 15:48) | 67 | 94 % |
| Anti-knight × killer × arrow by psninn (on 7. November 2024, 14:13) | 81 | 94 % |
| Gigglywhirl (Nabner Whisper) by tallcat (on 4. January 2025, 16:08) | 87 | 96 % |
| The Train and the Fly by marty_sears (on 16. August 2024, 11:13) | 102 | 95 % |
| Auf dem Oktoberfest by pirx (on 21. September 2013, 12:00) | 35 | 99 % |
| Die Kryptos - S01E06: ABC-Box by tuace (on 24. September 2017, 11:48) | 53 | 96 % |
| Partial Killer 1 by MavericksJD (on 23. September 2020, 09:41) | 59 | 93 % |
| Hybridsudoku, „Der kleine Trommler“ by glum_hippo (on 22. December 2020, 20:54) | 49 | 94 % |
| Sudoku Variants Series (307) - Sum Snake Sudoku by Richard (on 10. February 2021, 00:00) | 84 | 96 % |
| "Doughts" for Bigger by PetLov (on 12. March 2021, 10:00) | 15 | 95 % |
| Sagitta by Joseph nehme (on 29. May 2021, 06:13) | 40 | 94 % |
