(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 | |
|---|---|---|---|
 | whisperwhisperwhisperwhisper by twototenth (on 18. January 2022, 08:00) | 88 |  94 % |
| Whispering Isles by yttrio (on 18. January 2025, 01:44) | 90 | 97 % |
| Mnmle Mgntplttn by berni (on 11. April 2016, 14:13) | 36 | 98 % |
| Mehrdeutige Rätsel - U-Bahn unter Hochhäusern by Zzzyxas (on 30. November 2019, 17:28) | 38 | 99 % |
| The Spectrum of Sunlight by egubachu (on 20. December 2024, 15:31) | 46 | 90 % |
| The Yellow Jester (with aqjhs) by ChinStrap (on 16. October 2025, 14:20) | 37 | 97 % |
| Lace Agate by Niverio (on 4. June 2023, 09:56) | 130 | 95 % |
| Kombisudoku: Chaos - Pünktchen by Richard (on 11. January 2009, 20:28) | 126 | 93 % |
| Tauschpfad (2) by BFaw (on 27. August 2011, 13:20) | 30 | 91 % |
| Thermo-Sudoku: Some Assembly Required by trivial171 (on 6. May 2020, 04:10) | 33 | 99 % |
| Wrapping Paper on Boxing Day by twototenth (on 28. December 2021, 08:00) | 36 | 97 % |
| Dr. Sudoku by Hecspeed (on 9. September 2022, 08:28) | 27 | 98 % |
| Zeta and Kappa by twototenth (on 18. October 2022, 08:00) | 33 | 96 % |
| Diagonalization (Partial CC) by the_cogito (on 31. July 2023, 15:45) | 30 | 98 % |
| Shrug by dennischen (on 20. July 2024, 08:48) | 38 | 98 % |
| HERBST - Buchstabenrätsel / Letter Puzzle by DocLogic (on 28. October 2024, 10:10) | 27 | 97 % |
| Two Times a Killer by EnPee (on 2. January 2025, 00:12) | 27 | 91 % |
| Key West (Nurikabe/Fillomino) by The Book Wyrm (on 7. August 2025, 16:50) | 29 | 100 % |
| Yajilin Dutch Whispers by yttrio (on 7. September 2024, 01:37) | 70 | 97 % |
| Message in a bottle by NicoD (on 10. July 2025, 05:30) | 77 | 95 % |
