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 | |
|---|---|---|---|
![]() | Sherlock's advice to the good Dr. Watson by HalfBakedLunatic (on 4. June 2023, 15:36) | 91 | ![]() 98 % |
![]() | Odd Blockade Runners by JeffWajes (on 17. April 2023, 19:44) | 108 | ![]() 95 % |
![]() | Mousetrap? (A Rat Run Homage) by tallcat (on 16. January 2025, 06:00) | 214 | ![]() 98 % |
![]() | Die Kryptos - S03E05: Spiral City Construction by tuace (on 30. October 2018, 10:14) | 50 | ![]() 98 % |
![]() | Food Killer by Mark Sweep (on 27. November 2020, 10:00) | 25 | ![]() 98 % |
![]() | The Disjointed Cube by Wecoc (on 8. January 2021, 01:57) | 58 | ![]() 96 % |
![]() | Classic-style Killer Sudoku by Jeet Sampat (on 27. January 2022, 22:59) | 35 | ![]() 95 % |
![]() | Sum Hope (Sum Lines) by Chilly (on 26. April 2022, 11:23) | 50 | ![]() 97 % |
![]() | Kings and/or Knights by Scruffamudda (on 5. August 2022, 03:08) | 48 | ![]() 93 % |
![]() | The Friendly Stars by Crusader175 (on 10. January 2023, 15:00) | 28 | ![]() 98 % |
![]() | Death Stare by Die Hard (on 5. February 2023, 21:21) | 28 | ![]() 93 % |
![]() | Tetris Ain't In My Genes by Groktilian (on 3. October 2023, 16:00) | 29 | ![]() 93 % |
![]() | Ring of Fire by lmdemasi (on 18. December 2023, 15:55) | 56 | ![]() 94 % |
![]() | Club 27 (Thermo Sudoku) by Blashyrkh (on 22. March 2024, 22:12) | 96 | ![]() 99 % |
![]() | Molopo (XY-Differences Sudoku) by Qodec (on 29. March 2024, 15:34) | 74 | ![]() 95 % |
![]() | pollux by aqjhs (on 1. February 2025, 00:00) | 24 | ![]() 96 % |
![]() | Campground by Oripy (on 24. March 2025, 12:23) | 21 | ![]() 95 % |
![]() | Gee, Officer Kropki by EdTheAlchemist (on 18. November 2025, 13:08) | 52 | ![]() 96 % |
![]() | Scientific Method (Killer) by tallcat (on 5. March 2022, 04:46) | 90 | ![]() 97 % |
![]() | Pairs Party by Qodec (on 28. August 2021, 11:31) | 64 | ![]() 92 % |