(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 | |
|---|---|---|---|
 | Counterrotation by Jay Dyer (on 14. November 2021, 02:42) | 15 |  94 % |
| Close Friends by mathpesto (on 2. December 2021, 21:43) | 30 | 95 % |
| Schrödinger's Dots by starwarigami (on 18. December 2021, 02:34) | 53 | 99 % |
| Just Arrows! by Jeet Sampat (on 23. January 2022, 00:41) | 18 | 97 % |
| Nineteen? (X-sums Chaos Construction 2) by Lizzy01 (on 13. April 2022, 21:17) | 46 | 99 % |
| Ratio (-) Arrow Sudoku by Florian Wortmann (on 10. April 2022, 16:06) | 24 | 91 % |
| Order of Yevon by Tyrgannus (on 30. May 2022, 12:50) | 15 | 94 % |
| Who Likes Knights? by Yawnus (on 30. June 2022, 10:12) | 17 | 96 % |
| Mineshweepa by mnasti2 (on 10. August 2022, 20:45) | 23 | 94 % |
| Abstract Nonsense by Oddlyeven (on 13. August 2022, 23:34) | 66 | 97 % |
| Cartesian 159 by noswald (on 19. August 2022, 07:09) | 16 | 91 % |
| Sudoku Variants Series (387) - Adjacent Products Sudoku by Richard (on 5. October 2022, 02:00) | 63 | 93 % |
| Sashigane Sudoku by Ambrose (on 14. November 2022, 14:06) | 68 | 96 % |
| I'm a Vampire (Nicolas Cage) by gdc (on 6. August 2023, 20:48) | 20 | 98 % |
| Cold Sauerkraut (Nabner Thermo Sudoku) by Silverstep (on 24. August 2023, 17:47) | 28 | 91 % |
| Naked Filloku (Filloku #2) by mormagli (on 16. September 2023, 14:09) | 46 | 93 % |
| Jellyfish Jam [Anti-King Akari RGB] by wisty (on 26. October 2023, 02:46) | 14 | 100 % |
| BRIEFUMSCHLAG - Buchstabenrätsel / Letter Puzzle by DocLogic (on 17. December 2023, 14:21) | 27 | 96 % |
| Vertices by arbitrary (on 12. February 2024, 19:55) | 18 | 96 % |
| Hot Vaulted Banquet by Blobz (on 13. May 2024, 16:00) | 64 | 96 % |
