(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 | |
|---|---|---|---|
 | Enantiodromia (Yin-Yang Chaos Construction, 8x8) by thoughtbyte (on 3. August 2022, 00:05) | 26 |  99 % |
| Sudoku O.W.L. by Nahileon (on 10. October 2022, 21:25) | 24 | 100 % |
| Crypto Rotating Japanese Pentopia with Skyscrapers for ibag by KNT (on 10. July 2023, 00:51) | 26 | 99 % |
| Entropic Loop Chaos by yttrio (on 9. February 2024, 19:28) | 83 | 96 % |
| The Wandering Boi (Wrap Around, Chaos Construction) by DubiousMobius (on 24. July 2025, 00:38) | 28 | 100 % |
| Chaos Construction: Border Sums by KNT (on 24. April 2022, 22:24) | 59 | 95 % |
| Chaos Construction: Red Team / Blue Team by KNT (on 4. May 2024, 06:24) | 59 | 95 % |
| Steel Vengeance (Chaos Deconstruction Rollercoaster) by tallcat (on 2. September 2024, 08:00) | 58 | 98 % |
| -45 Killer by Mesmer (on 21. August 2020, 14:39) | 16 | 98 % |
| Taco Bowl 3 - Ring Of Fire by DiMono (on 19. March 2021, 16:15) | 43 | 99 % |
| Fireworks (Killer Arrow Sudoku) by FryTheGuy (on 2. June 2021, 07:12) | 19 | 91 % |
| Wanda's Hex by fjam (on 25. September 2021, 11:00) | 15 | 96 % |
| Jellyfish by grkles (on 15. October 2021, 01:49) | 25 | 98 % |
| Chaos Skyscrapers by JoWovrin (on 17. December 2021, 03:37) | 25 | 98 % |
| Tight Fit by TotallyNormalCat (on 30. December 2021, 19:00) | 57 | 98 % |
| Sudoku Assembly Required by Saphie (on 1. March 2022, 19:57) | 19 | 100 % |
| Colossal Fillomino with Sandwich Sudoku by MagnusJosefsson (on 28. September 2022, 15:50) | 71 | 100 % |
| Crypto Japanese Cave (Fillomino) by KNT (on 5. November 2022, 16:24) | 48 | 98 % |
| Trimodi (Modifier Entropy) by Mad-Tyas (on 10. January 2023, 00:48) | 18 | 95 % |
| Colossal Nurikabe Sudoku by Christounet (on 13. June 2023, 00:47) | 42 | 100 % |
