(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 | |
|---|---|---|---|
 | Copycat Collaboration by Scojo (on 28. June 2024, 13:38) | 59 |  99 % |
| Entangled (Diagonal Renban Killer Sudoku) by Phistomefel (on 26. September 2025, 22:36) | 109 | 96 % |
| Untitled Killer by Neb (on 9. June 2025, 15:00) | 125 | 98 % |
| U-Bahn unter Hochhäusern (Teil 5) by Zzzyxas (on 31. March 2012, 16:17) | 63 | 99 % |
| Japanischer Summen-Rundweg (knapp daneben, vielleicht) by Uhu (on 4. May 2017, 20:25) | 43 | 97 % |
| Snake Sum Sudoku 2 by Quarterthru (on 30. June 2020, 00:00) | 27 | 99 % |
| The 6 Sudokus of Christmas by Stavros96 (on 10. December 2020, 01:26) | 45 | 99 % |
| Yajilin Total/Regions 3 by Dandelo (on 4. January 2021, 22:10) | 25 | 99 % |
| Castle Wall by Mark Sweep (on 22. January 2021, 10:00) | 23 | 91 % |
| Thermo Arrow Sudoku by Lizzy01 (on 27. April 2021, 17:15) | 24 | 95 % |
| O/E Little Killers by JoWovrin (on 4. June 2021, 22:50) | 22 | 96 % |
| Which Direction? by Lisztes (on 7. December 2021, 01:00) | 24 | 97 % |
| Perpetual Motion of Kind '0' (Sudoku 26) by Sumanta(ANU) (on 12. May 2022, 13:51) | 25 | 93 % |
| An Actual Suguru Chaos Construction by mathpesto (on 22. May 2022, 16:32) | 92 | 99 % |
| Feudalism (No-touch region sum lines sudoku) by Qodec (on 3. March 2023, 21:26) | 50 | 97 % |
| This One Goes To Twelve by Blashyrkh (on 22. March 2023, 22:43) | 27 | 93 % |
| Intersections by Xenonetix (on 22. August 2023, 23:23) | 43 | 91 % |
| ⬯⬮⬯ Entropic-Sequence-Loop ⬮⬯⬮ (Easter Edition) by ElChiglia (on 30. March 2024, 07:15) | 23 | 92 % |
| Modern Art (Easter Special Edition) by Playmaker6174 (on 1. April 2024, 07:00) | 46 | 97 % |
| it said dry clean only by aqjhs (on 25. April 2025, 02:09) | 23 | 92 % |
