(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 | |
|---|---|---|---|
 | Antiknight Thermo Sudoku by PotatoHead21 (on 26. July 2023, 18:25) | 55 |  96 % |
| Heatstroke (Classic Thermo) by emmettcito (on 11. April 2021, 12:27) | 80 | 97 % |
| Fourteen (Killer Sudoku) by FryTheGuy (on 8. August 2021, 08:13) | 75 | 99 % |
| Sagitta (Anti-XV Arrow Sudoku) by Phistomefel (on 1. August 2022, 17:06) | 125 | 94 % |
| Unsichtbar Hochhauschaos by Luigi (on 22. November 2010, 12:54) | 36 | 95 % |
| Invisible Cages by Ennead (on 5. March 2023, 15:14) | 22 | 97 % |
| Red Bubbles by antiknight (on 12. April 2023, 22:35) | 22 | 91 % |
| Vivi Loca (Irregular Killer Sudoku) by Qodec (on 2. May 2023, 15:30) | 41 | 94 % |
| Ribbon World by Sniglett (on 3. December 2023, 03:31) | 40 | 95 % |
| Onion by the_cogito (on 7. November 2023, 17:10) | 79 | 98 % |
| Watchers Along the Cave by tesseralis (on 9. August 2022, 08:54) | 32 | 96 % |
| Neural Network by Xenonetix (on 26. November 2022, 14:41) | 38 | 95 % |
| Santa Puzzle - for dumediat by the_cogito (on 9. January 2023, 18:01) | 31 | 95 % |
| Crossroads by Knickolas (on 3. April 2023, 13:12) | 31 | 97 % |
| Bamboozled by NicoD (on 26. February 2025, 05:34) | 36 | 95 % |
| Rubber Bullets (10x10 Chaos Construction) by the_cogito (on 27. September 2022, 15:39) | 42 | 99 % |
| Uneven Terrain (Parity Cave Sudoku) by Nordy (on 29. January 2022, 20:15) | 21 | 94 % |
| Projections (Killer Parity) by tallcat (on 12. November 2022, 08:00) | 36 | 96 % |
| Menagerie by SSG (on 13. December 2022, 07:14) | 24 | 95 % |
| Yin Yang Yin by Xenonetix (on 22. January 2023, 22:22) | 38 | 92 % |
