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 | |
|---|---|---|---|
![]() | Friendly X-Sums (Chaos Construction) by thoughtbyte (on 16. July 2022, 23:11) | 42 | ![]() 99 % |
![]() | Doppelcrypto Japanese Cave by KNT (on 3. October 2023, 18:10) | 48 | ![]() 97 % |
![]() | Digital Loop by mathpesto (on 22. May 2025, 22:44) | 48 | ![]() 96 % |
![]() | A 38 III (toroidal) by tuace (on 28. October 2017, 13:19) | 24 | ![]() 99 % |
![]() | Poison Arrow by FryTheGuy (on 23. April 2021, 20:14) | 34 | ![]() 94 % |
![]() | Arrow Forest by PotatoHead21 (on 28. September 2021, 09:51) | 16 | ![]() 91 % |
![]() | One piece by lerroyy (on 25. September 2022, 22:48) | 27 | ![]() 98 % |
![]() | Nevermore Samurai by Kafkapharnaum (on 4. April 2023, 21:27) | 12 | ![]() 100 % |
![]() | Paper Snowflake (Irregular, Killer) by Chefofdeath (on 28. May 2023, 04:46) | 15 | ![]() 95 % |
![]() | Secret Kingdoms by SenatorGronk (on 27. March 2024, 17:36) | 28 | ![]() 98 % |
![]() | Wichtels Rätselsommer 2024 (5): Wätsel-Weihnacht by wichtel (on 29. August 2024, 20:23) | 14 | ![]() 95 % |
![]() | Thermal Doppelgangers by bodemeister (on 23. July 2025, 07:44) | 13 | ![]() 95 % |
![]() | Ʈɦᶒ Horoloɠᶖᶙḿ by ViKingPrime (on 2. August 2025, 00:00) | 14 | ![]() 100 % |
![]() | There's A Mole In Our Ranks by TripleABattery (on 31. August 2025, 18:03) | 16 | ![]() 91 % |
![]() | Wichtels Rätselherbst 2025 (2): Das heiße arktische Klima by wichtel (on 7. October 2025, 20:25) | 12 | ![]() 100 % |
![]() | So Near Yet So Far (Remote Sums Rollercoaster Chaos Deconstruction) by tallcat (on 23. January 2026, 20:00) | 41 | ![]() 98 % |
![]() | Thinkies (Miracle Chaos Construction) by purpl (on 12. June 2022, 18:12) | 37 | ![]() 98 % |
![]() | Whirlpool by FryTheGuy (on 26. August 2021, 17:16) | 27 | ![]() 96 % |
![]() | Cavino Wisteria by PrimeWeasel (on 9. November 2024, 09:48) | 28 | ![]() 100 % |
![]() | Ten-Oh (10-Lines sudoku) by Qodec (on 21. May 2023, 18:31) | 76 | ![]() 97 % |