(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 | |
|---|---|---|---|
 | Aquarium Sudoku by Sam Knott (on 20. June 2020, 13:07) | 26 |  93 % |
| Odd Trios Killer Sudoku by Quarterthru (on 19. September 2020, 12:00) | 26 | 99 % |
| Battle With The Archers 22: Double Speculations by Playmaker6174 (on 26. November 2021, 10:06) | 22 | 92 % |
| Leaning Tower Of ZooZ by Joseph nehme (on 7. January 2022, 18:47) | 94 | 97 % |
| Hopscotch (Remix) by Nordy (on 3. September 2022, 08:00) | 44 | 95 % |
| Robin Hood (Anti-king, Arrow Sudoku) by juddimal (on 2. September 2022, 23:39) | 24 | 92 % |
| SC27 - Arrows 2 by kuraban (on 14. December 2022, 21:16) | 24 | 97 % |
| Peaucellier-Lipkin by Palfly Kampling (on 22. July 2023, 05:20) | 26 | 97 % |
| Three Fluids (Nurikabe) by GemmaOane (on 23. September 2023, 20:25) | 27 | 92 % |
| Peel Back the Layers by XeonRisq (on 10. December 2023, 04:00) | 22 | 93 % |
| 4 Fanged Vampire by isajo4002 (on 18. October 2024, 20:03) | 20 | 93 % |
| Schrödinger's Killer by starwarigami (on 16. December 2021, 05:20) | 63 | 98 % |
| Iso by ICHTUES (on 19. December 2021, 06:00) | 64 | 96 % |
| 1001-Nacht-Rundwege aus Paralleluniversen by ibag (on 4. November 2013, 05:55) | 34 | 99 % |
| HALLOWEEN - gruseliges Buchstabenrätsel by DocLogic (on 24. October 2020, 13:13) | 39 | 99 % |
| Kropki-Arrow Party by abed hawila (on 6. November 2021, 09:40) | 38 | 98 % |
| Snake in the City by Lizzy01 (on 28. November 2021, 14:24) | 39 | 95 % |
| Nothing is Wrogn by Jay Dyer (on 20. November 2022, 19:49) | 127 | 95 % |
| Epiphany (Numbered Room and Region Sum Line) by Playmaker6174 (on 30. September 2022, 10:32) | 57 | 97 % |
| Whispering Caves by yttrio (on 28. September 2024, 02:49) | 55 | 99 % |
