(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 | |
|---|---|---|---|
 | I Want More Clues by EricRathbun (on 8. April 2023, 23:12) | 22 |  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 % |
| Split Pea Loup by yttrio (on 21. September 2024, 04:46) | 32 | 92 % |
| Cat Fun by Scojo (on 24. November 2024, 07:55) | 73 | 95 % |
| Nordschleife (Bosnian road/multiples pairs sudoku) by Qodec (on 29. November 2024, 20:31) | 52 | 95 % |
| Renban Caves by yttrio (on 11. January 2025, 02:59) | 139 | 98 % |
| 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 % |
| Twin Killer II by Richard (on 25. March 2009, 10:19) | 150 | 95 % |
| Eiskalte Magnetplatten by berni (on 16. December 2008, 22:28) | 109 | 95 % |
| Anti-Fortress Arrow Sudoku by Phistomefel (on 17. January 2021, 21:52) | 96 | 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 % |
| Spring Latch by Qodec (on 13. October 2023, 22:07) | 79 | 94 % |
| Orchid by mathpesto (on 6. September 2025, 19:03) | 78 | 97 % |
| Nothing is Wrogn by Jay Dyer (on 20. November 2022, 19:49) | 137 | 96 % |
| Magic Clone Knight Sudoku by Rotstein (on 27. May 2020, 01:04) | 35 | 92 % |
| Irregular Sandbattle Sudoku (Starbattle vs. Sandwich) by Osh Tirola (on 14. June 2020, 15:00) | 31 | 97 % |
