(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 | |
|---|---|---|---|
 | Sprawling by Xenonetix (on 14. April 2024, 01:01) | 37 |  97 % |
| Tetrakiller by Jay Dyer (on 31. May 2022, 15:17) | 82 | 98 % |
| Doppel-Killer Sudoku 0/1-9 by julius64 (on 27. January 2011, 22:21) | 46 | 94 % |
| Food Killer by Mark Sweep (on 27. November 2020, 10:00) | 24 | 97 % |
| Kropki XV Sudoku - Progressive Power-Up by DiMono (on 6. January 2022, 18:46) | 26 | 93 % |
| Domino Fever (Entropy Edition) by Mad-Tyas (on 21. February 2022, 23:32) | 71 | 94 % |
| Entropy Production by starwarigami (on 30. November 2022, 09:15) | 23 | 96 % |
| Kropkikabe by MmeMagique (on 28. May 2023, 18:00) | 22 | 92 % |
| Cage Match by silent_rob (on 29. July 2024, 08:00) | 26 | 93 % |
| Counterpoint (Renban Arrow) by tallcat (on 16. July 2022, 08:30) | 83 | 98 % |
| Even X-Sums by Realshaggy (on 24. December 2021, 05:00) | 46 | 97 % |
| Sompeo (Encaged Whispers) by ICHTUES (on 31. July 2022, 06:00) | 62 | 94 % |
| Waben Summenhochhauskropki Triple Invers und knapp daneben by Luigi (on 15. February 2010, 12:31) | 31 | 93 % |
| Loses Kalenderblatt April 2015 by April (on 1. April 2015, 00:00) | 28 | 98 % |
| Box killer sudoku by udukos (on 20. August 2020, 11:06) | 67 | 97 % |
| Earthquake in Sudokutown #2 by PrimeWeasel (on 14. January 2021, 17:39) | 27 | 99 % |
| Good Luck, Bad Luck by oberon (on 21. February 2022, 20:29) | 35 | 97 % |
| There's Something Off in This Sandwich by RockyRoer (on 8. April 2023, 21:08) | 34 | 99 % |
| Unzipped by marty_sears (on 30. October 2023, 00:41) | 31 | 95 % |
| Viper in the fog by Jolly Rogers (on 15. June 2024, 10:00) | 108 | 95 % |
