(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 | |
|---|---|---|---|
 | Khamodo Dragon (Japanese Sum Chaos Deconstruction) by MaizeGator (on 25. August 2025, 05:25) | 39 |  99 % |
| Die Kryptos - S03E06: Hochhausblöcke by tuace (on 30. October 2018, 10:15) | 30 | 98 % |
| Siamese Coral (2) by KNT (on 9. March 2023, 00:10) | 36 | 96 % |
| Chaos Meidjudokuluk by tesseralis (on 14. October 2023, 07:19) | 33 | 100 % |
| Hochhäuser in Japanischen Summen, Teil 2 by pirx (on 27. April 2017, 18:00) | 33 | 97 % |
| Palindrome Portals by TotallyNormalCat (on 1. January 2021, 23:00) | 42 | 91 % |
| Summation U-Bahn #6: Liar by Agent (on 30. November 2024, 09:00) | 30 | 100 % |
| Greater Doppelganger by Kafkapharnaum (on 15. January 2022, 17:54) | 38 | 98 % |
| Chaos Construction: Sightlines (2) by KNT (on 16. August 2022, 01:09) | 63 | 94 % |
| Derezzed by heliopolix (on 23. April 2024, 22:00) | 63 | 97 % |
| Rosette by Gliperal (on 26. August 2022, 02:43) | 27 | 95 % |
| Wichtel 2022 (2): Die neue Wichtel-U-Bahn by wichtel (on 6. September 2023, 09:09) | 28 | 98 % |
| Layla by mith (on 3. October 2022, 19:11) | 92 | 94 % |
| Wichtel 2016 (11): Frohe Weihnachten! by wichtel (on 1. October 2017, 22:00) | 26 | 92 % |
| Japanische Bahnhöfe, Teil 3 by pirx (on 27. May 2020, 13:00) | 27 | 99 % |
| Serial Duplex by Jay Dyer (on 29. October 2022, 17:46) | 35 | 98 % |
| Balance Loop Sudoku by Gliperal (on 15. December 2021, 21:07) | 56 | 95 % |
| Chaos Construction: Roller Coaster by KNT (on 9. February 2023, 01:18) | 81 | 98 % |
| Eternal Entropy by Mad-Tyas (on 28. September 2022, 12:15) | 35 | 94 % |
| Welcome, 2025! by Gliperal (on 1. January 2025, 14:45) | 52 | 93 % |
