(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 | |
|---|---|---|---|
 | Border skirmish (battlefield) sudoku by Nylimb (on 7. June 2020, 03:39) | 42 |  99 % |
| The French Connec7ion by Zombie Hunter (on 20. July 2021, 22:45) | 43 | 97 % |
| X-Sum Skyscraper (hybrid) by GarlicBredFries (on 15. November 2021, 07:53) | 33 | 95 % |
| A Day for Chaos by DarthParadox (on 31. March 2023, 20:40) | 43 | 91 % |
| The Quiet Whispers Between Loops by Jolly Rogers (on 30. September 2024, 20:28) | 38 | 94 % |
| Neue Post aus Rätselhausen by Statistica (on 1. December 2015, 00:12) | 48 | 95 % |
| Arrows and a Big X by GBPack (on 17. June 2021, 17:11) | 26 | 96 % |
| The Answer by tomate94 (on 4. May 2022, 11:18) | 25 | 95 % |
| Knight Sweats by SlowLarry (on 21. August 2022, 16:26) | 28 | 95 % |
| Jigsaw-doku by jwsinclair (on 3. October 2022, 20:31) | 22 | 98 % |
| Killer Inception by mnasti2 (on 27. October 2022, 23:00) | 25 | 96 % |
| Good Things Come in Threes by 3good5you (on 26. August 2023, 03:27) | 28 | 93 % |
| Fortune Cookie by pieguy (on 30. January 2024, 01:53) | 27 | 90 % |
| Distinctiveness by Ridhwan (on 12. February 2024, 00:05) | 25 | 92 % |
| Scorpion by udukos (on 1. January 2022, 14:10) | 59 | 96 % |
| 10+ Line Sudoku by Phistomefel (on 1. September 2022, 10:03) | 173 | 98 % |
| Little Killer Between Sudoku by SudokuExplorer (on 24. August 2021, 02:00) | 34 | 96 % |
| Urban Renewal (11x11 deconstruction) by jwsinclair (on 24. May 2022, 21:25) | 42 | 96 % |
| Equal sum chaos by Testarossa (on 2. June 2022, 16:01) | 39 | 93 % |
| Chaotic Sums by kuraban (on 26. October 2022, 19:34) | 76 | 97 % |
