(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 | |
|---|---|---|---|
 | Renban Plasters by antiknight (on 4. April 2024, 18:32) | 36 |  93 % |
| Knighten by Testarossa (on 24. January 2022, 21:37) | 74 | 96 % |
| Adventsportale, Teil 3 by pirx (on 16. December 2018, 12:00) | 37 | 98 % |
| XY-Cages by glum_hippo (on 1. May 2022, 06:05) | 36 | 96 % |
| Hidden X-Sums by RockyRoer (on 8. August 2022, 17:48) | 35 | 99 % |
| Sealed Fate by Xendari (on 15. August 2022, 05:55) | 36 | 96 % |
| X-Sumaguni Sudoku by rockratzero (on 15. April 2023, 08:22) | 36 | 95 % |
| Six-pack Linked Sudokus #3 by Genomico (on 25. February 2021, 03:49) | 43 | 91 % |
| Sequential Killer Sudoku by SenatorGronk (on 3. August 2020, 15:22) | 52 | 99 % |
| Quetzalcoatl by Tyrgannus (on 24. September 2021, 21:29) | 47 | 93 % |
| June Pentomino Month (3) - Filled Liar Loop by Richard (on 21. June 2013, 12:00) | 53 | 97 % |
| Sudoku Variants Series (288) - Battlefield Sudoku by Richard (on 30. September 2020, 00:00) | 62 | 97 % |
| Sudoku Variants Series (306) - Square Crow Sudoku by Richard (on 3. February 2021, 00:00) | 59 | 95 % |
| Madrigal by Fafrd (on 1. January 2023, 17:41) | 102 | 93 % |
| ABC-Box mit Hochhauskern (2) by ibag (on 3. July 2013, 08:05) | 62 | 99 % |
| Identitätskrise (Variables Tapasyu 2) by usp (on 8. March 2014, 16:20) | 58 | 96 % |
| Japanisches Summen by berni (on 4. September 2015, 21:14) | 28 | 98 % |
| Wichtel 2018 (1): Tapa mit U-Bahn und Hochhaushinweisen by wichtel (on 31. May 2019, 12:08) | 48 | 99 % |
| Roller Coaster U-Bahn by Zzzyxas (on 22. August 2019, 18:25) | 51 | 99 % |
| Palindromic Snake by Phistomefel (on 18. March 2020, 00:38) | 67 | 94 % |
