(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 | |
|---|---|---|---|
 | Invisible Thermometers by Nahileon (on 17. May 2023, 12:51) | 48 |  93 % |
| Japanese Nurikabe (2) by KNT (on 6. September 2022, 02:52) | 56 | 100 % |
| Wave Particles by TotallyNormalCat (on 22. April 2021, 19:00) | 64 | 98 % |
| Heart Breaker (Arrow Sudoku) by FryTheGuy (on 27. May 2021, 03:36) | 15 | 92 % |
| 4D Arrow Sudoku by FryTheGuy (on 6. July 2021, 11:20) | 13 | 98 % |
| Belagerungsturm by Myxo (on 22. September 2024, 14:12) | 31 | 98 % |
| Cyclone (Secret Satan 4-in-1 Sudoku/Shading/Loop Hybrid) by MaizeGator (on 5. January 2025, 03:30) | 16 | 96 % |
| Fillomenon by DarthParadox (on 2. October 2023, 19:14) | 117 | 97 % |
| Afterlife (Yin Yang Fillomino Deconstruction) by Agent (on 15. November 2022, 09:00) | 65 | 98 % |
| Hell's Coordinates (Sudoku) by Piatato (on 4. January 2023, 13:16) | 25 | 100 % |
| Doubler Twin Deconstruction by Christounet (on 29. January 2025, 18:19) | 23 | 99 % |
| Chaos Construction: Aquarium (2) by KNT (on 23. June 2022, 01:08) | 60 | 100 % |
| Archery Target by Nahileon (on 24. April 2022, 15:48) | 40 | 97 % |
| Entropia (Skyscraper, Entropy) by Mad-Tyas (on 16. January 2023, 12:15) | 49 | 92 % |
| Außerirdische Krypto Killer Pyramide by tuace (on 30. April 2014, 20:00) | 23 | 99 % |
| Das Prinzip der Polarität by tuace (on 3. September 2017, 17:16) | 24 | 96 % |
| Wichtel 2017 (8): Ein rätselhaftes Experiment by wichtel (on 17. August 2018, 03:05) | 36 | 100 % |
| Miracle Clones [Tribute to Botaku] by Undar_Beyond (on 10. November 2020, 20:34) | 30 | 91 % |
| Fission (Classic Thermo) by emmettcito (on 7. May 2021, 12:37) | 28 | 95 % |
| Gin (11x11 Deconstruction) by lerroyy (on 13. November 2022, 23:51) | 24 | 99 % |
