(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 | |
|---|---|---|---|
 | [50 Puzzles Celebration] Double Trouble Entropy by Mad-Tyas (on 30. January 2022, 03:49) | 37 |  100 % |
| Vikavolt by tesseralis (on 14. September 2022, 05:41) | 36 | 94 % |
| Cages Constriction (Slitherlink Chaos Construction Sudoku) by rockratzero (on 8. April 2023, 10:43) | 41 | 94 % |
| 3... 2... 1... Meteor Strike! by igniteice (on 28. November 2023, 16:04) | 44 | 90 % |
| Compass Chaos Construction by Jay Dyer (on 11. March 2023, 20:08) | 63 | 98 % |
| Overlooked by IcyFruit (on 7. November 2025, 12:21) | 88 | 97 % |
| Magic Sandwich Sudoku by Madmahogany (on 10. May 2020, 20:22) | 27 | 99 % |
| 3D Killer Sudoku by SlowLarry (on 21. May 2020, 17:32) | 18 | 96 % |
| Mysterious Samurai (Hard Ver. of Sudoku Challenge 2020) by Kwaka (on 12. September 2020, 23:40) | 17 | 94 % |
| Arrows X by emmettcito (on 7. February 2021, 20:47) | 17 | 92 % |
| Odd X-Sums by Realshaggy (on 25. December 2021, 05:00) | 57 | 96 % |
| The Toppling Tree by fjam (on 9. January 2022, 19:29) | 29 | 99 % |
| Venomous Snakes by lepton (on 2. February 2023, 16:27) | 38 | 99 % |
| Ban it twice! (Yin Yang, Renban) by Paletron (on 17. August 2023, 22:41) | 17 | 98 % |
| Photonic Crystal Wings by heliopolix (on 14. October 2023, 02:47) | 18 | 100 % |
| Sega Cages by Prof.Dori (on 31. December 2023, 15:17) | 16 | 95 % |
| Devious Ability: Buy Free! by Elytron (on 22. August 2024, 20:57) | 19 | 94 % |
| Tinker by randall (on 21. September 2024, 09:18) | 28 | 91 % |
| U-Bahn LITSO (8x9) by the_cogito (on 4. December 2024, 21:34) | 16 | 94 % |
| Chessdoku-1: The London System by .proxz14 (on 20. February 2025, 14:43) | 14 | 92 % |
