(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 | |
|---|---|---|---|
 | The 3-Colour Theorem by starwarigami (on 10. February 2023, 19:54) | 100 |  96 % |
| 3 Linked Sudokus by JonaS2010 (on 12. May 2019, 17:24) | 70 | 94 % |
| 10:01 AM by CaptZebraCakes (on 10. November 2023, 00:30) | 62 | 96 % |
| Kreuzzahlrätsel (4) by berni (on 21. October 2010, 11:57) | 41 | 92 % |
| Bernis Geburtstag - Japanische Summen auf Klein'scher Flasche by ibag (on 15. June 2013, 15:25) | 36 | 95 % |
| Die Kryptos - S02E02: A 38 by tuace (on 16. March 2018, 15:10) | 41 | 95 % |
| NATUR - Buchstabenrätsel by DocLogic (on 2. January 2020, 16:41) | 43 | 92 % |
| 10-in-9 killer sudoku #2 by Nylimb (on 30. January 2020, 12:36) | 42 | 96 % |
| Omaha by zetamath (on 21. June 2024, 04:57) | 40 | 96 % |
| Roller Coaster by Uhu (on 2. November 2016, 13:21) | 70 | 98 % |
| Wichtelkalender 2013 - August by SilBer (on 1. August 2013, 00:00) | 52 | 99 % |
| Carrousel - (Little) Killer / Sandwich Sudoku by SlowLarry (on 23. August 2020, 21:32) | 29 | 97 % |
| Two Sides of a Domino by TotallyNormalCat (on 30. June 2021, 20:30) | 52 | 92 % |
| Arrow - Canal View by abed hawila (on 7. January 2022, 13:06) | 50 | 98 % |
| Battle With The Archers 33: Between Friends and Enemies (part 3) by Playmaker6174 (on 21. June 2022, 08:52) | 29 | 97 % |
| Lost by Joseph nehme (on 24. June 2022, 19:30) | 57 | 96 % |
| Matthew 15:14 by Ennead (on 23. August 2022, 01:41) | 26 | 100 % |
| Quagmire by jwsinclair (on 7. February 2023, 20:48) | 62 | 97 % |
| Arrow Courtyard by PotatoHead21 (on 16. February 2023, 10:33) | 30 | 95 % |
| Palenban (Renban+palindrome sudoku) by Qodec (on 11. September 2023, 20:28) | 65 | 93 % |
