(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 | |
|---|---|---|---|
 | Numbers in Cages in Regions in a 6x6 by PeterJoe (on 29. September 2023, 14:58) | 29 |  97 % |
| Stealth (feat. tallcat) by the_cogito (on 11. November 2022, 04:10) | 78 | 94 % |
| Milchstraße (Sektor 23F) by usp (on 5. November 2014, 00:00) | 48 | 98 % |
| Shady Combination #1: Cave, Pentominos, Slitherlink, Snake by Myxo (on 9. January 2023, 15:33) | 38 | 99 % |
| Froschteich by Myxo (on 25. August 2024, 15:01) | 43 | 93 % |
| Skymania: Wolkenkratzer-Hanidoku by Pyrrhon (on 18. September 2009, 12:29) | 60 | 91 % |
| Killer Pyramide by tuace (on 3. October 2013, 02:30) | 67 | 94 % |
| Skyscrapers 9*9 by cdwg2000 (on 12. September 2020, 18:37) | 45 | 97 % |
| Glass Skyscraper Sudoku(P2) by cdwg2000 (on 25. September 2020, 07:39) | 15 | 90 % |
| Sandwich Sudoku--Odd or Even(CSC2020 Leftover) by cdwg2000 (on 21. October 2020, 16:06) | 17 | 96 % |
| Handshake by Asimir (on 13. May 2021, 03:10) | 18 | 94 % |
| The Butterfly Effect - Region Sum Lines Sudoku by Mr.Menace (on 28. February 2022, 20:11) | 97 | 97 % |
| Assassin9 (Irregular Killer Arrow Sudoku) by Ore (on 5. May 2022, 00:00) | 16 | 96 % |
| Parcae by Kafkapharnaum (on 20. August 2022, 18:18) | 15 | 96 % |
| Division Cell by billybobo445 (on 12. May 2023, 04:48) | 48 | 97 % |
| Maverick by Kafkapharnaum (on 27. August 2023, 08:10) | 16 | 100 % |
| ZandwYch by ICHTUES (on 10. September 2023, 06:00) | 31 | 97 % |
| Herding Cats by jsmirob (on 24. September 2023, 22:33) | 16 | 94 % |
| Happy Anniversary Mum & Dad! by ThePedallingPianist (on 26. September 2024, 23:34) | 52 | 96 % |
| Stabelle by ICHTUES (on 14. August 2023, 11:00) | 97 | 97 % |
