(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 | |
|---|---|---|---|
 | U-Bahn by cyddrdrd (on 11. April 2026, 00:00) | 20 |  100 % |
| Cave of Loops by Myxo (on 7. December 2022, 11:52) | 65 | 99 % |
| Ereignisreiches Rätseljahr by Zzzyxas (on 31. December 2013, 06:00) | 26 | 97 % |
| Kurodoku by yttrio (on 27. July 2024, 02:27) | 116 | 98 % |
| Für Rollo zum Geburtstag: Speichenrätsel by CHalb (on 23. June 2017, 23:58) | 32 | 95 % |
| yin yang john (conway) by aqjhs (on 8. April 2025, 01:50) | 38 | 94 % |
| Count Me In by oskode (on 5. March 2026, 11:45) | 79 | 94 % |
| got too many pages stuck together by aqjhs (on 8. November 2025, 08:11) | 43 | 99 % |
| Bunte Geburtstagstorte by Luigi (on 4. November 2014, 00:56) | 31 | 96 % |
| Anti-Knight Arrow Sudoku by MeloMania! (on 29. October 2020, 16:23) | 20 | 91 % |
| Snake Parents by lepton (on 21. January 2023, 07:25) | 18 | 96 % |
| Suradewoku (Geradeweg/Sudoku) by Wessel Strijkstra (on 14. July 2023, 01:39) | 19 | 98 % |
| Chock-a-Block by marty_sears (on 14. May 2024, 01:46) | 90 | 97 % |
| Grow outside the grid by Lizzy01 (on 8. February 2025, 01:24) | 15 | 93 % |
| Lost Town (Lost and Found #6) by .proxz14 (on 15. March 2025, 10:00) | 55 | 94 % |
| Revivify by Jay Dyer (on 12. July 2025, 11:20) | 83 | 94 % |
| Sliced Chaos Production by RockyRoer (on 27. November 2022, 12:37) | 49 | 98 % |
| Call My Bluff (2 Truths, 1 Lie Sudoku) by tallcat (on 16. October 2023, 07:00) | 97 | 97 % |
| The Serpent Devouring Rome by JeffWajes (on 18. March 2024, 01:16) | 31 | 92 % |
| [TSL] Scenic Railroad by Myxo (on 23. December 2024, 09:24) | 31 | 99 % |
