(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 | |
|---|---|---|---|
 | Sandwich Fillomino #3 by Mark Sweep (on 31. December 2021, 10:00) | 17 |  96 % |
| Alphanumeric by jwsinclair (on 15. December 2021, 20:24) | 16 | 98 % |
| Cowgirl by OhHeyGuysItsMax (on 18. February 2022, 19:34) | 52 | 92 % |
| Alpes by lerroyy (on 26. February 2022, 20:52) | 22 | 91 % |
| Viper Valley Trail Map (Triple Snake Sudoku) by Nordy (on 20. March 2022, 04:43) | 15 | 98 % |
| Assassin9 (Irregular Killer Arrow Sudoku) by Ore (on 5. May 2022, 00:00) | 18 | 96 % |
| Cycle Sandwich by SirSchmoopy (on 16. May 2022, 23:08) | 20 | 93 % |
| Frankly by wooferzfg (on 20. July 2022, 17:44) | 16 | 93 % |
| I Want More Clues by EricRathbun (on 8. April 2023, 23:12) | 21 | 96 % |
| Gouge Away by mathpesto (on 7. April 2024, 17:31) | 148 | 98 % |
| Muddlebug by Tyrgannus (on 17. June 2024, 09:12) | 41 | 95 % |
| Misshapen Skyscrapers by Belamis (on 19. June 2024, 21:20) | 19 | 94 % |
| Nordschleife (Bosnian road/multiples pairs sudoku) by Qodec (on 29. November 2024, 20:31) | 52 | 95 % |
| Jam Packed Thick Crust Club Sandwich by sfushidahardy (on 13. February 2025, 00:43) | 33 | 95 % |
| Entropic Tens by ebiggie (on 12. March 2025, 00:04) | 21 | 91 % |
| Eiskalte Magnetplatten by berni (on 16. December 2008, 22:28) | 109 | 95 % |
| TLDR by Abdul the Killer (on 28. May 2024, 12:34) | 117 | 94 % |
| Anti-Fortress Arrow Sudoku by Phistomefel (on 17. January 2021, 21:52) | 95 | 93 % |
| Glatt by ICHTUES (on 23. October 2022, 06:00) | 54 | 95 % |
| GP24 Leftover: Japanische Summen + Magnetplatten by ibag (on 24. March 2024, 20:24) | 40 | 99 % |
