(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 | |
|---|---|---|---|
 | Belagerungsturm by Myxo (on 22. September 2024, 14:12) | 44 |  98 % |
| Doubler Twin Deconstruction by Christounet (on 29. January 2025, 18:19) | 38 | 99 % |
| The inconvenient square root (chaos construction) by filuta (on 19. December 2021, 13:30) | 40 | 99 % |
| The Victoria Sandwich Is A Lie by fjam (on 8. June 2022, 17:50) | 20 | 97 % |
| Entropy Evolution by Mad-Tyas (on 30. November 2022, 09:01) | 22 | 90 % |
| Japanese Sums #1: Killer Cages by lerroyy (on 15. February 2023, 19:52) | 21 | 96 % |
| Jet Lag (Dynamic Fog of War, Chaos Construction) by DubiousMobius (on 6. December 2024, 04:21) | 22 | 96 % |
| SubwaYY to H... ? [Secret Satan #2] by Christounet (on 4. January 2025, 16:24) | 19 | 100 % |
| wanna double dutch? by aqjhs (on 15. September 2025, 21:21) | 21 | 100 % |
| Chaos Deconstruction: Japanese Sum by Phistomefel (on 13. February 2023, 20:00) | 116 | 98 % |
| Wichtel 2020 (4): Memo an den Weihnachtsmann by wichtel (on 27. April 2021, 02:02) | 17 | 98 % |
| Heart Breaker (Arrow Sudoku) by FryTheGuy (on 27. May 2021, 03:36) | 20 | 94 % |
| Riverbank - Episode 4: Nessie by henrypijames (on 20. May 2022, 09:26) | 18 | 98 % |
| Tiger's Jaw by Samish (on 8. August 2022, 19:23) | 19 | 94 % |
| Hell's Coordinates (Sudoku) by Piatato (on 4. January 2023, 13:16) | 37 | 99 % |
| Chaos In Frankfurt! (Secret Satan 2023) by Niverio (on 1. January 2024, 17:25) | 40 | 100 % |
| Region Geometry X by kolot (on 2. June 2022, 00:28) | 50 | 98 % |
| Schrödinger's Deconstruction by mathpesto (on 19. June 2022, 13:57) | 57 | 98 % |
| Nuriquarium Sudoku by Jay Dyer (on 26. January 2023, 12:46) | 57 | 93 % |
| Crypto Lying Japanese Cavescraper Ring for polar by KNT (on 20. December 2022, 02:44) | 37 | 99 % |
