(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 | |
|---|---|---|---|
 | Leaning Tower Of ZooZ by Joseph nehme (on 7. January 2022, 18:47) | 103 |  97 % |
| Polka Dot by PotatoHead21 (on 26. March 2023, 18:47) | 108 | 94 % |
| Pliers (Anti-King Thermo Sudoku) by Phistomefel (on 17. October 2022, 08:44) | 259 | 97 % |
| HALLOWEEN - gruseliges Buchstabenrätsel by DocLogic (on 24. October 2020, 13:13) | 42 | 99 % |
| Times Square by grkles (on 5. November 2021, 16:56) | 38 | 94 % |
| Very old burger (German Whisper + Kropki + Antiknight Sudoku) by Sktx (on 17. September 2022, 16:50) | 58 | 95 % |
| City of Skyscrapers by Kitty Trouble (on 5. November 2023, 14:45) | 40 | 96 % |
 | Coral Corridor by Sotehr (yesterday, 00:50) | 46 | 96 % |
| Anti-Knight Killer Sudoku #2 by udukos (on 2. March 2021, 10:19) | 68 | 95 % |
| Star of Bethlehem by Aspartagcus (on 25. December 2025, 03:25) | 66 | 95 % |
| Halcyon by NicoD (on 27. December 2025, 05:30) | 66 | 98 % |
| Little Killer Sudoku #2 by Phistomefel (on 25. March 2020, 15:42) | 105 | 96 % |
| Sudoku Variants Series (245) - Counting Neighbours Sudoku by Richard (on 4. December 2018, 00:00) | 109 | 93 % |
| Thermo-Sudoku: Some Assembly Required by trivial171 (on 6. May 2020, 04:10) | 35 | 99 % |
| Pocket Sandwich Sudoku by Genomico (on 1. November 2020, 20:25) | 16 | 92 % |
| Boba by grkles (on 20. April 2021, 18:28) | 30 | 94 % |
| Jigsaw by PotatoHead21 (on 20. June 2021, 19:54) | 22 | 90 % |
| Anti-Sudoku by HawkAvatar (on 21. June 2021, 14:02) | 14 | 98 % |
| (anti) R5nban Arrow Windoku by Jeroen Panda (on 29. July 2021, 09:44) | 16 | 98 % |
| Two's Company by apiyo (on 11. September 2021, 05:52) | 17 | 94 % |
