(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 | |
|---|---|---|---|
 | Fearful Symmetry (Renban Killer) by tallcat (on 28. April 2025, 05:00) | 194 |  97 % |
| A tilt at full rank by ralphwaldo1 (on 8. February 2025, 19:16) | 111 | 98 % |
| XV Kropki Sudoku by Philipp Huber (on 28. November 2020, 15:14) | 80 | 94 % |
| Wingnuts by FullDeck-Missing (on 7. September 2024, 13:09) | 72 | 92 % |
| Pentonimo Kakuro by julius64 (on 4. May 2013, 14:24) | 53 | 96 % |
| Godzilla in Sudokutown by FryTheGuy (on 21. September 2021, 05:35) | 57 | 98 % |
| Wrogn Answers Only by jwsinclair (on 19. October 2022, 19:44) | 214 | 98 % |
| Area 81 by mathpesto (on 31. January 2023, 19:44) | 91 | 96 % |
| Equality Cube by Sniglett (on 4. December 2023, 00:56) | 46 | 96 % |
| ROCK STAR - Buchstabenrätsel by DocLogic (on 5. February 2020, 19:28) | 38 | 92 % |
| Atom by Jobo (on 8. May 2024, 21:34) | 45 | 90 % |
| Clapping on the 1 and 3 by cristophermoore (on 6. November 2023, 00:00) | 81 | 94 % |
| Japanische Summen modulo 3 by ibag (on 6. August 2012, 07:46) | 71 | 98 % |
| Dumbstruck by NicoD (on 28. August 2025, 05:30) | 43 | 98 % |
| Madness by jwsinclair (on 12. March 2023, 20:20) | 37 | 96 % |
| Waves by RandyDan (on 10. January 2026, 12:04) | 34 | 92 % |
| 3’s A Charm - Kropki/Arrow Sudoku by Mr.Menace (on 24. July 2023, 20:46) | 43 | 92 % |
| Zipper Sandwich by RockyRoer (on 17. January 2024, 15:23) | 35 | 97 % |
| LM-Qualitraining 2019 (7): U-Bahn unter Hochhäusern by Zzzyxas (on 16. March 2019, 20:19) | 63 | 99 % |
| Krazy Kropki Killer by vidarino (on 19. November 2021, 13:35) | 30 | 93 % |
