(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 | |
|---|---|---|---|
 | 10+ Line Sudoku by Phistomefel (on 1. September 2022, 10:03) | 176 |  98 % |
| Habitat 67 by sfushidahardy (on 15. October 2024, 18:35) | 66 | 97 % |
| Equal sum chaos by Testarossa (on 2. June 2022, 16:01) | 39 | 93 % |
| Chaotic Sums by kuraban (on 26. October 2022, 19:34) | 78 | 97 % |
| Doom Loop (Filloku #6) by mormagli (on 12. November 2023, 17:30) | 38 | 98 % |
| Circuit Board [Standard U-Bahn] by wisty (on 14. November 2023, 17:10) | 35 | 99 % |
| Hide and Xeek by HalfBakedLunatic (on 24. December 2023, 03:32) | 44 | 94 % |
| Hurra: Zafer ist 33! by Richard (on 30. August 2012, 00:00) | 48 | 97 % |
| Renban X-sums sudoku by udukos (on 20. July 2021, 19:45) | 43 | 100 % |
| Boxes Clash by Niverio (on 1. May 2022, 09:43) | 50 | 98 % |
| Boxed In (German Whispers Renban Sudoku) by Cane_Puzzles (on 3. September 2021, 17:50) | 64 | 98 % |
| Castle Wall Fillomino by Agent (on 21. March 2023, 09:00) | 60 | 97 % |
| Mut zur Lücke! by Wuschel (on 28. October 2023, 16:14) | 65 | 98 % |
| These Aren't The Circles You're Looking For by Jay Dyer (on 7. August 2024, 00:02) | 75 | 97 % |
| EnTropic Islands by Paletron (on 1. October 2023, 11:27) | 139 | 98 % |
| DEF Hochhaus anders rum by Luigi (on 13. July 2011, 08:47) | 23 | 93 % |
| Roller Coaster by Uhu (on 2. November 2016, 13:21) | 72 | 98 % |
| U-Bahn mit gemischten Hinweisen (Teil 2) by Zzzyxas (on 28. December 2019, 13:32) | 45 | 99 % |
| The Soused Snake by Big Tiger (on 30. June 2020, 02:23) | 16 | 95 % |
| Crossguard Lightsaber Sudoku by Stavros96 (on 29. October 2020, 13:01) | 26 | 94 % |
