(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 | |
|---|---|---|---|
 | Japanische Inseln, Krypto by pirx (on 28. February 2015, 17:00) | 28 |  99 % |
| Differenzen zwischen Summen III (kryptisch) by tuace (on 17. August 2018, 13:23) | 29 | 99 % |
| Chaos Construction: 2nd Region Sight Sum (9x9) by Playmaker6174 (on 26. April 2024, 05:30) | 30 | 98 % |
| Taijitu (ft. KNT) by TotallyNormalCat (on 26. May 2022, 18:00) | 50 | 97 % |
| Parity Party X - "Sir Launcelot" by glum_hippo (on 7. June 2020, 06:52) | 18 | 91 % |
| Krop Kages by Philipp Huber (on 13. February 2021, 22:44) | 18 | 98 % |
| Daredevil (clone + thermo sudoku) by Aspartagcus (on 4. March 2021, 22:21) | 40 | 95 % |
| Quantum X by starwarigami (on 16. January 2022, 12:01) | 19 | 98 % |
| Chaotically Coordinated Arrows by Piatato (on 3. March 2022, 19:58) | 55 | 97 % |
| Wichtel 2021 (6): Flucht durch die Unterwelt by wichtel (on 24. September 2022, 02:21) | 16 | 100 % |
| Yin-Yang Compass Fillomino by MagnusJosefsson (on 13. October 2022, 14:59) | 36 | 100 % |
| Modern Wall by XeonRisq (on 29. March 2023, 19:00) | 17 | 98 % |
| Suguru Chaos Deconstruction #5: Region Sums by mathpesto (on 23. March 2022, 01:51) | 95 | 98 % |
| Sunken Treasure Chaos Construction by Schwupel (on 24. July 2022, 18:58) | 24 | 96 % |
| vpermb by zzw (on 25. October 2023, 05:30) | 23 | 99 % |
| The Method of Differences by DarthParadox (on 16. December 2023, 21:06) | 26 | 95 % |
| Seeing Around the Corner by Die Hard (on 8. July 2024, 00:07) | 27 | 98 % |
| Fillomino Chaos Construction by dennischen (on 23. May 2023, 08:46) | 60 | 100 % |
| Chaos Construction: Yin Yang (9x9) by Jesper (on 22. May 2022, 10:39) | 96 | 100 % |
| Crypto Japanese Cave (2) by KNT (on 13. October 2022, 23:25) | 60 | 100 % |
