(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 | |
|---|---|---|---|
 | Chaos Construction: Snake by MagnusJosefsson (on 5. June 2021, 13:58) | 46 |  97 % |
| Carousel by twototenth (on 10. August 2021, 08:00) | 28 | 99 % |
| Knotted Arrows by antiknight (on 20. April 2022, 22:34) | 34 | 91 % |
| Syzygies of Susurrus by JayForty (on 3. March 2023, 21:55) | 29 | 92 % |
| DTMF (Dual Tone Multi-Frequency) by ebiggie (on 24. March 2025, 02:58) | 19 | 94 % |
| Consechaos Bonsai by Xenonetix (on 12. May 2025, 19:19) | 34 | 97 % |
| Zodiac Project: the year of the dög by aqjhs (on 20. November 2025, 00:55) | 33 | 98 % |
| Summation U-Bahn #5: Sorted Clues by Agent (on 22. October 2024, 09:00) | 32 | 97 % |
| Hurricane by SudokuExplorer (on 16. March 2021, 01:00) | 63 | 98 % |
| Flying Arrows by antiknight (on 2. March 2022, 19:36) | 47 | 92 % |
| Castle in the Sky by filuta (on 23. April 2023, 12:35) | 18 | 94 % |
| Lobster Bisque (Chaos Construction) by Tacosian (on 23. November 2023, 21:57) | 39 | 99 % |
| Saturnalia by mathpesto (on 13. January 2024, 05:19) | 90 | 93 % |
| Vertigo Yajilin #2 by Piatato (on 7. May 2024, 17:47) | 19 | 98 % |
| Semi-Symmetry by Lizzy01 (on 20. September 2024, 11:44) | 25 | 97 % |
| A Degree in Thermology by Knickolas (on 26. November 2024, 21:51) | 44 | 97 % |
| River Crossing by IcyFruit (on 22. February 2024, 14:37) | 91 | 98 % |
| TENtropy by Mad-Tyas (on 9. May 2023, 09:02) | 48 | 94 % |
| Neodymium (Double Cave Japanese Sums) by Agent (on 4. June 2024, 09:00) | 47 | 99 % |
| Chaos Construction: Yin Yang (9x9) by Jesper (on 22. May 2022, 10:39) | 115 | 100 % |
