(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 | |
|---|---|---|---|
 | Anti-Arrow by Eclectic_Hoosier (on 12. October 2022, 06:28) | 16 |  93 % |
| Target Acquired (Equalines Sudoku) by Sktx (on 4. February 2023, 22:17) | 26 | 96 % |
| Cave Express (Japanese Sums Cipher) by Agent (on 21. February 2023, 09:00) | 56 | 99 % |
| Parasite by XeonRisq (on 10. March 2023, 17:00) | 27 | 93 % |
| Birefringence by Jay Dyer (on 25. August 2023, 20:46) | 64 | 96 % |
| Sea Level Rise Sudoku by MagnusJosefsson (on 31. March 2024, 18:58) | 19 | 98 % |
| Orbicular by egubachu (on 12. May 2024, 20:37) | 17 | 93 % |
| Typhon by Kafkapharnaum (on 24. August 2024, 19:41) | 33 | 98 % |
| Fingertrap (disjoint) by SkepticalMario (on 28. August 2024, 00:00) | 20 | 95 % |
| Dynamic Domino Sums by Jolly Rogers (on 22. May 2025, 18:53) | 40 | 94 % |
| pull prank by aqjhs (on 6. September 2025, 06:09) | 30 | 100 % |
| 24HPC-Überbleibsel: Magnetschwebebahn by CJK (on 18. September 2025, 08:00) | 19 | 100 % |
| Don't Fret by ViKingPrime (on 8. October 2025, 04:00) | 16 | 93 % |
| Zodiac Project: Astrolabe by Sotehr (on 30. October 2025, 00:00) | 46 | 98 % |
| Thermal Equilibrium (Chaos Construction) by Agent (on 19. July 2022, 09:00) | 104 | 99 % |
| Nonconsecutive Killer Sudoku by spxtr (on 1. January 2021, 06:21) | 108 | 96 % |
| Team Sum Sudoku by Phistomefel (on 7. May 2024, 19:32) | 91 | 97 % |
| Breakthrough by Xenonetix (on 3. March 2023, 03:03) | 70 | 97 % |
| Chaos Construction: Region Sums by KNT (on 7. April 2022, 20:42) | 66 | 97 % |
| Chequered Arromino #2 by Phistomefel (on 25. May 2023, 20:32) | 108 | 99 % |
