(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 | |
|---|---|---|---|
 | Suradewoku (Geradeweg/Sudoku) by Wessel Strijkstra (on 14. July 2023, 01:39) | 16 |  100 % |
| Chaos Construction: Double Arrow by Xendari (on 14. November 2023, 02:19) | 74 | 96 % |
| 200 Streams of Zetatude by Chilly (on 28. December 2023, 14:25) | 14 | 100 % |
| Rellik Galaxies by TripleABattery (on 9. February 2024, 15:00) | 16 | 92 % |
| Chackstones (XVXV/Kropki pairs/X-sums) by dumediat (on 27. April 2024, 02:42) | 35 | 92 % |
| Is V Greater Than, Less Than, or Equal to 5? (Revised) by HalfBakedLunatic (on 17. May 2024, 22:36) | 28 | 92 % |
| Marmoset by jwsinclair (on 2. July 2024, 16:05) | 26 | 97 % |
| Lazy River (w/ Nordy) by mathpesto (on 8. February 2024, 18:27) | 73 | 96 % |
| Suguru Chaos Deconstruction: Zipper Lines by ONeill (on 24. December 2023, 04:34) | 58 | 99 % |
| Japanese Sums with Arrows by mathpesto (on 31. December 2021, 22:24) | 35 | 94 % |
| Bridges by Xenonetix (on 21. May 2022, 01:35) | 35 | 90 % |
| Capulet [Variant Sudoku] by wisty (on 18. June 2022, 05:36) | 40 | 97 % |
| Microchip by wooferzfg (on 23. July 2022, 02:19) | 38 | 97 % |
| Double, Double by zetamath (on 13. August 2022, 22:07) | 81 | 97 % |
| Unter der Lupe (Instructionless) by Myxo (on 27. September 2023, 10:20) | 34 | 99 % |
| The Friendly Knights by Bert (on 13. February 2024, 05:07) | 36 | 93 % |
| Vampires by Mad-Tyas (on 23. January 2023, 11:06) | 68 | 95 % |
| Icing disaster (Region sum lines/X-sums) by dumediat (on 30. June 2023, 22:38) | 69 | 93 % |
| Airlocks (Pentominous) by Gliperal (on 17. May 2021, 01:04) | 28 | 92 % |
| Tapa Mashup with Clones by Mark Sweep (on 25. February 2022, 10:00) | 32 | 98 % |
