(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 4-Colour Theorem by starwarigami (on 5. February 2023, 10:00) | 73 |  96 % |
| Sun Chariot by Miky (on 14. April 2021, 00:17) | 36 | 94 % |
| A kyler map [BYO Killer Deconstruction] by Christounet (on 16. October 2023, 18:29) | 29 | 97 % |
| The Fifteenth Day of Christmas by cristophermoore (on 18. December 2022, 07:01) | 48 | 98 % |
| Di-agony! by ThePedallingPianist (on 24. November 2022, 17:07) | 61 | 97 % |
| Zum Geburtstag by Uhu (on 9. July 2017, 00:00) | 38 | 98 % |
| Where are the cage totals? - Odd/Even killer sudoku (#5) by Mr.Menace (on 2. February 2021, 10:12) | 30 | 94 % |
| Poltrona by ICHTUES (on 8. May 2022, 05:58) | 27 | 100 % |
| Purple Archery Arrows by antiknight (on 9. October 2022, 17:25) | 54 | 94 % |
| Cryptocombination Knapp Daneben by KNT (on 26. March 2023, 15:26) | 25 | 98 % |
| FMTC by Starstorm (on 20. June 2023, 21:21) | 12 | 98 % |
| Doubler XL by thoughtbyte (on 6. September 2023, 00:07) | 54 | 99 % |
| Matchaluck (A Meidjuluk N=15 Variant) by PrimeWeasel (on 11. October 2023, 11:41) | 14 | 100 % |
| Chaos Sudok-U-Bahn by Christounet (on 21. February 2024, 15:33) | 26 | 98 % |
| Pêcher pour pêches (Killer Sudoku with Same Size Same Sum) by purpl (on 27. April 2024, 23:58) | 15 | 93 % |
| Semi-Symmetry by Lizzy01 (on 20. September 2024, 11:44) | 16 | 95 % |
| The Graveyard Of Knapp Daneben by fjam (on 12. October 2024, 14:59) | 12 | 91 % |
| Four houses of Kropki by filuta (on 6. March 2022, 17:42) | 34 | 90 % |
| Surround Set by PrimeWeasel (on 11. February 2022, 12:12) | 20 | 97 % |
| Ancient Tablet by Kafkapharnaum (on 25. July 2023, 15:51) | 20 | 100 % |
