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
|
|---|
 | Palindromic Snake
by Phistomefel (on 18. March 2020, 00:38) | 76 | 
94 %
|
| Anti-Springer Killer, "Postkarte vom Mars"
by glum_hippo (on 3. November 2021, 02:16) | 39 |
90 %
|
| Regional Variants (ambiguous region sum lines)
by AnalyticalNinja (on 4. June 2022, 02:54) | 40 |
97 %
|
| Parroty Lines
by marty_sears (on 29. April 2024, 13:52) | 191 |
96 %
|
| Nurikabe Kurotto
by Paletron (on 12. June 2024, 10:57) | 34 |
94 %
|
| Deadly Dance of 7 and 8
by NXTMaster (on 23. January 2026, 00:00) | 36 |
94 %
|
| Bagels & Deli
by ICHTUES (on 3. September 2023, 06:00) | 46 |
97 %
|
| Loopy Whisper 'Wich
by yttrio (on 24. May 2024, 21:47) | 43 |
96 %
|
| The Knight's Battle Axe
by masetab (on 15. November 2025, 04:52) | 56 |
94 %
|
| Chaos Circles (Updated)
by SenatorGronk (on 10. October 2023, 19:54) | 118 |
98 %
|
| Sandwiches for Table Four
by RockyRoer (on 22. March 2023, 10:25) | 62 |
96 %
|
| Portal Dolmen 2 (Anti-Knight, German Whispers, ESL)
by juddimal (on 24. May 2025, 22:30) | 68 |
93 %
|
| Daybreak (Antiknight Thermo Sudoku)
by Playmaker6174 (on 11. October 2022, 04:47) | 100 |
98 %
|
| Wichtel 2018 (1): Tapa mit U-Bahn und Hochhaushinweisen
by wichtel (on 31. May 2019, 12:08) | 52 |
99 %
|
| Murder on the Orient Express - killer sudoku
by KevinCelis (on 18. July 2020, 00:07) | 14 |
95 %
|
| Little Killer Sudoku #3
by Phistomefel (on 12. September 2020, 11:05) | 68 |
93 %
|
| Surveyor Sudoku
by stephane.bura (on 1. October 2020, 20:00) | 17 |
98 %
|
| X-Distance Sudoku(2)——Hard
by cdwg2000 (on 18. November 2020, 16:47) | 26 |
92 %
|
| 真笑Puzzles031--69Sandwiches (5)--Nonconsecutive Double Sandwich
by cdwg2000 (on 28. February 2021, 10:46) | 12 |
93 %
|
| Killer Sudoku 311
by Quarterthru (on 20. March 2021, 12:00) | 34 |
97 %
|
