(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 | |
|---|---|---|---|
 | Schrödinger's Deconstruction by mathpesto (on 19. June 2022, 13:57) | 50 |  98 % |
| Crux by Jay Dyer (on 22. October 2023, 16:09) | 89 | 97 % |
| Chaos In Frankfurt! (Secret Satan 2023) by Niverio (on 1. January 2024, 17:25) | 38 | 100 % |
| Jet Lag (Dynamic Fog of War, Chaos Construction) by DubiousMobius (on 6. December 2024, 04:21) | 18 | 96 % |
| Mini-Colossal Octoquadri II: U-Bahn by sfushidahardy (on 20. March 2025, 02:53) | 18 | 100 % |
| Region Geometry X by kolot (on 2. June 2022, 00:28) | 44 | 99 % |
| 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 % |
| 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) | 15 | 98 % |
| ABC-Box Hybrid 2: Numbered Room (12x12) by Playmaker6174 (on 8. July 2024, 12:30) | 18 | 100 % |
| Zodiac Project: Leo by ChinStrap (on 16. July 2025, 13:54) | 31 | 95 % |
| Wave Particles by TotallyNormalCat (on 22. April 2021, 19:00) | 69 | 99 % |
| Fillomenon by DarthParadox (on 2. October 2023, 19:14) | 129 | 97 % |
| 4D Killer Sudoku by FryTheGuy (on 11. October 2021, 22:29) | 28 | 100 % |
| Japanese Nurikabe (2) by KNT (on 6. September 2022, 02:52) | 58 | 100 % |
| Gin (11x11 Deconstruction) by lerroyy (on 13. November 2022, 23:51) | 27 | 99 % |
