(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 | |
|---|---|---|---|
 | Stammtisch-Teamrätsel mit Portalen by CJK (on 12. August 2023, 19:08) | 47 |  99 % |
| Rooks are Better by meggen033 (on 23. September 2022, 09:43) | 139 | 94 % |
| ♫ Slitherlink take me home ♫ by Phistomefel (on 1. April 2022, 01:04) | 57 | 99 % |
| Odd/Even Sandwich Sudoku by Piatato (on 2. August 2021, 13:33) | 51 | 92 % |
| Quad sums sudoku by udukos (on 17. August 2021, 18:07) | 52 | 95 % |
| 4x4 Arrow XV Sudokus by SudokuExplorer (on 1. April 2022, 08:00) | 47 | 94 % |
| Tilting by SSG (on 2. June 2022, 07:03) | 50 | 100 % |
| Somedokus Are Friendly Dokus by juggler (on 15. April 2024, 20:39) | 52 | 96 % |
| May XL-Month (5) - Blackout Domino by Richard (on 31. May 2013, 12:00) | 60 | 96 % |
| Pixy Stix by thoughtbyte (on 18. April 2024, 20:32) | 57 | 94 % |
| Chaos Construction: Glow by Xenonetix (on 7. February 2022, 01:00) | 67 | 94 % |
| Undec-ided by SirSchmoopy (on 11. April 2022, 00:06) | 78 | 98 % |
| Pile of 15 (Killer Sudoku) by Cane_Puzzles (on 2. December 2022, 15:51) | 69 | 94 % |
| Yin Yang Position Sums Sudoku by Jesper (on 3. November 2022, 19:17) | 76 | 97 % |
| Twin Killer IV (B) by Richard (on 6. August 2010, 12:00) | 77 | 94 % |
| Sudoku Variants Series (377) - Little Palindromes Sudoku by Richard (on 27. July 2022, 02:00) | 81 | 97 % |
| Krypt-Rundweg verkehrt by lupo (on 8. July 2009, 14:35) | 25 | 96 % |
| Teilchenzoo - Einzelkind by lupo (on 24. February 2013, 07:37) | 37 | 99 % |
| ABC-Box mit Buchstabensalat-Kern mit Hochhaus-Kern by ibag (on 14. July 2013, 23:18) | 64 | 99 % |
| Knapp-daneben-Kryptos (6): Japanische Summen by ibag (on 2. February 2014, 21:29) | 58 | 98 % |
