(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 | |
|---|---|---|---|
 | GENIAL - Buchstabenrätsel / Letter Puzzle by DocLogic (on 24. May 2022, 20:49) | 32 |  98 % |
| 6x6 wrogn CC by lerroyy (on 6. June 2022, 00:07) | 43 | 94 % |
| Double Negative by Scruffamudda (on 9. June 2022, 00:32) | 62 | 94 % |
| Viewpoint by Xenonetix (on 24. June 2022, 02:22) | 24 | 98 % |
| Penrod by krangune (on 25. June 2022, 13:03) | 18 | 91 % |
| Blackjack by EricRathbun (on 28. January 2023, 23:50) | 19 | 92 % |
| Topsy-Turvy by zetamath (on 1. August 2022, 19:41) | 80 | 97 % |
| Matthew 15:14 by Ennead (on 23. August 2022, 01:41) | 30 | 99 % |
| Sandwich Recipes by Andrewsarchus (on 11. September 2022, 08:17) | 11 | 93 % |
| Spoiled Child by Perladel (on 11. September 2022, 11:30) | 15 | 95 % |
| Toroidal Region XY-Sums (Chaos Construction, 8x8) by thoughtbyte (on 15. September 2022, 00:11) | 22 | 98 % |
| Nosy Neighbors by Ambrose (on 18. September 2022, 18:21) | 13 | 96 % |
| Average Sudoku 3 by Lyun Licuss (on 19. September 2022, 10:08) | 19 | 98 % |
| Arrowslits by antiknight (on 19. September 2022, 18:50) | 38 | 94 % |
| Hooked (Run-on Renbans/X-sums) by dumediat (on 23. September 2022, 20:38) | 16 | 94 % |
| Mongoose by Pallando (on 7. October 2022, 02:25) | 18 | 100 % |
| Sasayaki Misaki (Whispering Cape) - Nurimisaki/German Whispers Sudoku by rockratzero (on 10. October 2022, 18:09) | 15 | 96 % |
| Bird of Paradise (Segmented Region Sum Lines) by AnalyticalNinja (on 18. October 2022, 01:11) | 15 | 98 % |
| Sum Thing Irregular by tallcat (on 3. November 2022, 19:41) | 46 | 95 % |
| The Arkenstone by Blobz (on 11. November 2022, 16:00) | 50 | 97 % |
