(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 | |
|---|---|---|---|
 | Ricochet (Arrow Killer) by tallcat (on 11. June 2021, 16:01) | 54 |  91 % |
| Polar Vortex by mathpesto (on 2. October 2022, 22:42) | 45 | 91 % |
| The Graveyard Of Shadows by fjam (on 22. September 2022, 19:02) | 74 | 97 % |
| Außerirdischer und Osterhase by ibag (on 20. April 2014, 05:10) | 24 | 96 % |
| Maximal Anti-Killer Sudoku by Madmahogany (on 17. July 2020, 23:12) | 32 | 94 % |
| Lying Stars 2 (Liar Partial Killer) by Djmelee3000 (on 21. September 2020, 06:02) | 27 | 94 % |
| Eight Xs (XV sudoku) by Lisztes (on 19. November 2020, 01:00) | 26 | 93 % |
| Toffee by pieguy (on 30. April 2024, 04:02) | 30 | 95 % |
| Alligator by zetamath (on 21. February 2025, 16:09) | 30 | 91 % |
| Happy Holiday! by Richard (on 15. July 2011, 12:00) | 55 | 91 % |
| Parity Party (Odd-Even coded) by Realshaggy (on 11. February 2021, 21:55) | 24 | 98 % |
| Connections by TotallyNormalCat (on 6. June 2021, 23:00) | 29 | 99 % |
| 6 PM Reservation... by Sktx (on 25. October 2021, 18:15) | 27 | 91 % |
| Entroguity by twototenth (on 26. July 2022, 08:00) | 26 | 93 % |
| ❤ by psninn (on 13. November 2024, 15:11) | 27 | 94 % |
| Fillomino U-Bahn by KNT (on 1. May 2023, 23:28) | 54 | 100 % |
| Pointing Digits Sudoku by clover (on 3. February 2024, 20:03) | 82 | 96 % |
| Primetime (Mystery Killer) by Mad-Tyas (on 11. August 2021, 00:14) | 26 | 96 % |
| A Bright Idea by SenatorGronk (on 5. January 2022, 01:55) | 30 | 93 % |
| Imperfect Flower (Run-on Renbans) by AnalyticalNinja (on 6. October 2022, 23:06) | 28 | 95 % |
