(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 | |
|---|---|---|---|
 | Chaos Construction: Increasing Path by KNT (on 3. October 2022, 23:31) | 105 |  96 % |
| Region Geometry X by kolot (on 2. June 2022, 00:28) | 45 | 99 % |
| Not One Black Dot by mormagli (on 11. February 2023, 04:50) | 20 | 95 % |
| Crux by Jay Dyer (on 22. October 2023, 16:09) | 90 | 97 % |
| Mini-Colossal Octoquadri II: U-Bahn by sfushidahardy (on 20. March 2025, 02:53) | 18 | 100 % |
| Japanese Icewalk (2) by KNT (on 21. August 2025, 00:48) | 34 | 92 % |
| Außerirdische Krypto Killer Pyramide by tuace (on 30. April 2014, 20:00) | 30 | 99 % |
| Quite a Mouthful by Gliperal (on 2. January 2021, 23:49) | 31 | 96 % |
| Chaos Construction: Miracle on 81 Cells by Playmaker6174 (on 17. September 2025, 07:00) | 33 | 97 % |
| Invisible Thermometers by Nahileon (on 17. May 2023, 12:51) | 52 | 94 % |
| Chaos Construction : Wrogn by lerroyy (on 8. June 2022, 20:59) | 69 | 98 % |
| Chaos Construction: Regional Chess Sums by Nordy (on 7. January 2022, 08:00) | 15 | 96 % |
| Hell's Coordinates (Sudoku) by Piatato (on 4. January 2023, 13:16) | 30 | 100 % |
| Japanese Sums #2: Killer Cages Fillomino by lerroyy (on 3. March 2023, 14:29) | 16 | 98 % |
| ABC-Box Hybrid 2: Numbered Room (12x12) by Playmaker6174 (on 8. July 2024, 12:30) | 19 | 100 % |
| Sabal (Colossal Fillomino Sudoku) by sfushidahardy (on 22. April 2025, 22:01) | 37 | 100 % |
| The Graveyard Of Emptiness by fjam (on 10. October 2025, 20:02) | 60 | 94 % |
| Wave Particles by TotallyNormalCat (on 22. April 2021, 19:00) | 69 | 99 % |
| Japanese Nurikabe (2) by KNT (on 6. September 2022, 02:52) | 59 | 100 % |
| Afterlife (Yin Yang Fillomino Deconstruction) by Agent (on 15. November 2022, 09:00) | 70 | 98 % |
