(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 | |
|---|---|---|---|
 | District 9 by tesseralis (on 17. August 2022, 10:15) | 25 |  100 % |
| Double Agent by DadJokes (on 29. September 2022, 21:48) | 29 | 98 % |
| Prism Redux by SeaOtter417 (on 2. November 2022, 15:47) | 35 | 91 % |
| huisgenoot gezocht by aqjhs (on 8. December 2025, 01:59) | 29 | 100 % |
| Northwest Wind by SXH (on 22. December 2024, 07:06) | 37 | 91 % |
| A Ranked Phenomenon by Las4one (on 25. December 2025, 05:00) | 36 | 96 % |
| Zadra by IcyFruit (on 14. March 2024, 15:55) | 71 | 95 % |
| el veloz murciélago hindú by aqjhs (on 6. November 2024, 18:12) | 51 | 92 % |
| Doppelter Rundweg by rob (on 25. June 2014, 11:05) | 51 | 99 % |
| Japanische Summen 2358 by Uhu (on 3. September 2017, 17:47) | 57 | 98 % |
| Shikasudoku 2 by Qodec (on 12. February 2022, 12:09) | 57 | 95 % |
| Dutch Baby - a Snake Egg Sudoku by glum_hippo (on 13. January 2024, 07:17) | 70 | 96 % |
| Sudoku Variants Series (290) - Product Ltd Sudoku by Richard (on 14. October 2020, 00:00) | 76 | 94 % |
| Arrow Sudoku X - Third time's the charm by udukos (on 3. April 2021, 21:26) | 52 | 96 % |
| Mosaic cogs [Extended diagonal XV - virtual sudoku] by SimplePurpleFrog (on 2. November 2021, 04:05) | 26 | 100 % |
| Hyperloop (Double Trouble) by Mad-Tyas (on 10. November 2021, 13:53) | 23 | 98 % |
| Five Stories by SSG (on 6. January 2022, 07:15) | 25 | 94 % |
| Arrow City by PotatoHead21 (on 18. January 2022, 20:32) | 44 | 95 % |
| Heat Map by Scruffamudda (on 21. April 2022, 01:23) | 17 | 93 % |
| Chaos Construction: Internal X-Sums by KNT (on 11. July 2022, 23:23) | 78 | 97 % |
