(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 | |
|---|---|---|---|
 | T Time by EricRathbun (on 23. March 2022, 21:44) | 32 |  97 % |
| Prime Directive by DiMono (on 15. April 2023, 15:35) | 15 | 92 % |
| Modular Loop by SamuPiano (on 8. November 2023, 05:29) | 13 | 94 % |
| Spirality by Nordy (on 6. June 2024, 08:30) | 17 | 92 % |
| Triples by zetamath (on 3. November 2021, 03:40) | 66 | 96 % |
| Maria by dennischen (on 9. March 2024, 06:46) | 54 | 90 % |
| Dutch Flat Mates (Japanese Sums) by Flinty (on 9. October 2024, 11:30) | 92 | 93 % |
| Japanische Krypto-Summen gratulieren by pin7guin (on 9. July 2016, 00:00) | 57 | 98 % |
| Heatmap Sudoku by Jesper (on 13. June 2020, 16:19) | 43 | 97 % |
| The Maltese Zipper by Oddlyeven (on 31. December 2023, 16:06) | 48 | 96 % |
| Modular Yin Yang by yttrio (on 17. January 2026, 03:20) | 101 | 97 % |
| Zahlenbild-Rundweg by Calavera (on 22. June 2009, 16:07) | 130 | 96 % |
| Christmas Cat Run by phil_the (on 2. January 2025, 14:25) | 39 | 94 % |
