(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 | |
|---|---|---|---|
 | Liar Japanese Sums: 48 Hour Special by SamuPiano (on 12. August 2024, 15:44) | 19 |  97 % |
| 90's nostalgia by aqjhs (on 12. September 2024, 17:04) | 23 | 93 % |
| Infiltration by XeonRisq (on 19. February 2025, 22:00) | 24 | 93 % |
| Etude for a Broken Piano by juggler (on 3. May 2025, 19:44) | 43 | 96 % |
| ON EDGE: Brown & Green by marty_sears (on 9. February 2025, 11:08) | 186 | 97 % |
| Pixy Stix by thoughtbyte (on 18. April 2024, 20:32) | 54 | 94 % |
| KOPF - Buchstabenrätsel / Letter Puzzle by DocLogic (on 13. September 2020, 12:55) | 36 | 96 % |
| Positive Ring by SudokuExplorer (on 19. January 2021, 02:00) | 78 | 96 % |
| Miraculous Modular Loop by yttrio (on 22. September 2023, 20:30) | 75 | 94 % |
| Lots of Fun by heliopolix (on 29. May 2024, 20:49) | 33 | 96 % |
| Different Neighbours U-Bahn by Paletron (on 2. June 2024, 11:30) | 38 | 96 % |
| Focus by FlowJo (on 21. March 2022, 22:37) | 57 | 97 % |
| Obstructed Skyline (fog) by jwsinclair (on 20. August 2023, 18:13) | 131 | 91 % |
| Nightfall (German Whisper combo) by Playmaker6174 (on 22. October 2022, 22:29) | 72 | 96 % |
| Killer sudoku 2011 - 2012 by Richard (on 31. December 2011, 13:00) | 76 | 93 % |
| Kleine Hochhausserie: Finale (von allem etwas) by CHalb (on 9. December 2013, 12:03) | 43 | 97 % |
| Mini-Höhle (2) by r45 (on 20. November 2018, 17:29) | 33 | 91 % |
| Toroidal Chess Sudoku #3 - Thermo by Rotstein (on 10. June 2020, 21:07) | 19 | 96 % |
| Z-Sums Sudoku 3 by Semax (on 4. October 2020, 08:21) | 17 | 98 % |
| Araf's Lunchbox (6x6) by udukos (on 17. June 2021, 21:54) | 13 | 98 % |
