(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 | |
|---|---|---|---|
 | Ten Ring Circus by JeffWajes (on 30. December 2025, 06:27) | 131 |  98 % |
| Thermal Equilibrium (Chaos Construction) by Agent (on 19. July 2022, 09:00) | 104 | 99 % |
| Team Sum Sudoku by Phistomefel (on 7. May 2024, 19:32) | 92 | 97 % |
| Breakthrough by Xenonetix (on 3. March 2023, 03:03) | 72 | 97 % |
| Chaos Construction: Region Sums by KNT (on 7. April 2022, 20:42) | 67 | 97 % |
| Chequered Arromino #2 by Phistomefel (on 25. May 2023, 20:32) | 109 | 99 % |
| Nurikiller 2 by mathpesto (on 4. April 2023, 13:53) | 82 | 100 % |
| Summation U-Bahn by Agent (on 19. September 2023, 09:00) | 70 | 97 % |
| Peristaltikmaschine (Chaos Construction) by glum_hippo (on 21. March 2025, 12:32) | 72 | 98 % |
| Chaos Construction: Arachne by tesseralis (on 24. September 2022, 08:20) | 32 | 97 % |
| Coral Subway by wooferzfg (on 26. March 2023, 22:35) | 30 | 96 % |
| Lunch box by Qodec (on 18. August 2020, 11:18) | 33 | 97 % |
| Mysterious Boxes by fjam (on 8. January 2023, 16:19) | 26 | 91 % |
| Pretending (with ChinStrap) by MSDOS (on 9. June 2025, 21:56) | 26 | 97 % |
| Rule of Thirds by sfushidahardy (on 15. October 2025, 17:19) | 27 | 100 % |
| Killer Sudoku - Twirl by Phistomefel (on 6. December 2020, 11:18) | 77 | 98 % |
| 10-in-9 Killer Sudoku by KNT (on 10. May 2022, 01:14) | 48 | 97 % |
| 2T1L by ICHTUES (on 11. September 2022, 06:00) | 70 | 96 % |
| Wichtel 2015 (12 und Schluss): Hommage an eine Künstlerin by wichtel (on 18. July 2016, 21:50) | 34 | 96 % |
| Puffer Fish by Qodec (on 28. November 2020, 22:05) | 51 | 98 % |
