(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 | |
|---|---|---|---|
 | Wichtelkalender 2014 - Monat Oktober by r45 (on 1. October 2014, 00:00) | 52 |  99 % |
| Papers, Please [Anti-knight, German Whispers] by Justalilguy (on 5. August 2025, 22:23) | 64 | 91 % |
| Bob the Killer by mellowrobinson (on 14. June 2025, 04:33) | 102 | 96 % |
| 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 % |
