(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 | |
|---|---|---|---|
 | Semi-Symmetry by Lizzy01 (on 20. September 2024, 11:44) | 25 |  97 % |
| Doubler Trickery by Mad-Tyas (on 12. October 2024, 12:33) | 21 | 93 % |
| A Degree in Thermology by Knickolas (on 26. November 2024, 21:51) | 44 | 97 % |
| Cage Play 6: Killer 357 Multiples by HalfBakedLunatic (on 18. May 2025, 17:50) | 22 | 94 % |
| Japanische Höhle mit Irrwisch von den Außerirdischen (2) by ibag (on 20. April 2018, 00:00) | 41 | 100 % |
| Neodymium (Double Cave Japanese Sums) by Agent (on 4. June 2024, 09:00) | 47 | 99 % |
| Eddies by Qodec (on 12. January 2021, 22:41) | 73 | 99 % |
| Arrowings by kolot (on 25. January 2022, 11:37) | 27 | 96 % |
| Suguru Chaos Deconstruction: Solo Little Killers by crispy16 (on 10. April 2022, 21:17) | 83 | 97 % |
| Twin Rooms (Chaos Construction) by Agent (on 14. June 2022, 09:00) | 49 | 96 % |
| Regional Chaos by arbitrary (on 11. January 2025, 19:00) | 25 | 95 % |
| Dynamic Duos by Niverio (on 22. August 2021, 17:32) | 51 | 98 % |
| Snack'O'Mino [Level #2] by Christounet (on 9. March 2023, 12:47) | 56 | 100 % |
| The Cross by Tom1i (on 15. December 2020, 15:06) | 62 | 99 % |
| Deconstructed Whiski by mathpesto (on 7. July 2022, 20:48) | 65 | 99 % |
| Odd Pentominoes on the Loose by JeffWajes (on 31. July 2022, 05:52) | 31 | 97 % |
| vpermb by zzw (on 25. October 2023, 05:30) | 31 | 99 % |
| Dismay (Region Sum Lines Sudoku) by Qodec (on 29. June 2022, 22:50) | 77 | 97 % |
| Daredevil (clone + thermo sudoku) by Aspartagcus (on 4. March 2021, 22:21) | 47 | 94 % |
| Japanese Sum Cave Cipher: Fillomino (Parity) by Niverio (on 18. November 2022, 18:32) | 41 | 100 % |
