(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 | |
|---|---|---|---|
 | Sum-Product Snake by kolot (on 22. July 2021, 08:23) | 23 |  99 % |
| World of Weird Wonders - A 7x7 Irregular Sudoku Pack by Playmaker6174 (on 18. December 2021, 10:35) | 22 | 93 % |
| Faces by Pallando (on 11. March 2022, 11:53) | 24 | 100 % |
| Piatato's challenge by filuta (on 2. July 2022, 18:01) | 27 | 95 % |
| Cliques by purpl (on 22. August 2022, 22:40) | 26 | 92 % |
| Ocular by Maxentius (on 19. December 2022, 21:24) | 28 | 91 % |
| Japanische Summen mit Hochhaushinweisen by Zzzyxas (on 6. September 2024, 00:00) | 41 | 99 % |
| Terra Incognita (with ChinStrap) by sujoyku (on 4. July 2025, 16:11) | 52 | 95 % |
| Kurtosis by juggler (on 19. August 2025, 23:45) | 84 | 91 % |
| Zhōngguó Ěryǔ by Prof.Dori (on 9. September 2025, 19:30) | 22 | 92 % |
| Goldilocks by NicoD (on 20. February 2026, 05:30) | 98 | 97 % |
| Crossbow (Arrow variant sudoku) by Qodec (on 10. July 2024, 15:34) | 81 | 94 % |
| Thermal Nights by abed hawila (on 24. April 2021, 20:29) | 182 | 98 % |
| Sherlock's advice to the good Dr. Watson by HalfBakedLunatic (on 4. June 2023, 15:36) | 93 | 98 % |
| Tower of Babel by Jay Dyer (on 6. June 2023, 17:47) | 155 | 96 % |
| Stranger in a Strange Land by Wuschel (on 24. February 2025, 10:58) | 160 | 98 % |
| Palindrome Sandwiches by RockyRoer (on 13. March 2021, 12:26) | 29 | 99 % |
| Clockwork Yajilin: Parity Point by wisty (on 28. February 2024, 01:00) | 28 | 97 % |
| Splitting hairs (Equal split lines) by Lizzy01 (on 13. April 2025, 17:40) | 37 | 94 % |
| Marble hodgepodge by NicoD (on 5. April 2025, 05:27) | 33 | 93 % |
