(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 | |
|---|---|---|---|
 | Qaak (Quattroquadri/Anti-diagonal/Arrow/Killer) by dumediat (on 24. August 2024, 15:50) | 41 |  94 % |
| Polka Dot by PotatoHead21 (on 26. March 2023, 18:47) | 100 | 95 % |
| Naked Filloku (Filloku #2) by mormagli (on 16. September 2023, 14:09) | 43 | 93 % |
| Pliers (Anti-King Thermo Sudoku) by Phistomefel (on 17. October 2022, 08:44) | 234 | 97 % |
| The 27 Cage Run by AFrayedKnot (on 24. September 2020, 21:12) | 27 | 92 % |
| /4 /5 by Nahileon (on 18. March 2022, 11:03) | 54 | 99 % |
| Tutotu by Fafrd (on 10. June 2022, 02:35) | 24 | 98 % |
| Double or Nothing by Oddlyeven (on 14. December 2022, 17:06) | 23 | 99 % |
| Yin Yang Squares by Celery (on 21. January 2023, 00:04) | 28 | 94 % |
| Killer RBC1-6 by RockyRoer (on 3. February 2023, 11:42) | 26 | 94 % |
| A Christmas Vacation Around the World (CTC Secret Santa 2023) by Niverio (on 27. December 2023, 15:11) | 29 | 90 % |
| Lime Lines II by Calesch (on 10. March 2024, 21:03) | 26 | 92 % |
| Landvermessung U-Bahn #1 by The Book Wyrm (on 4. April 2024, 21:40) | 22 | 98 % |
| Shrug by dennischen (on 20. July 2024, 08:48) | 34 | 97 % |
| Schrödinger's Dots by starwarigami (on 18. December 2021, 02:34) | 51 | 99 % |
| Abstract Nonsense by Oddlyeven (on 13. August 2022, 23:34) | 62 | 97 % |
| DSM 2023 Leftover: Full Rank Sudoku by uvo (on 5. July 2023, 12:00) | 52 | 91 % |
| Japanische Summen gerade - ungerade by ibag (on 1. August 2012, 22:10) | 82 | 99 % |
| Negative Caving by Mark Sweep (on 11. December 2020, 10:00) | 28 | 96 % |
| Wichtel 2020 (2): Die Himmelsbahn by wichtel (on 30. March 2021, 22:00) | 28 | 99 % |
