(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 | |
|---|---|---|---|
 | U-Bahn mit gemischten Hinweisen (Teil 3) by Zzzyxas (on 28. December 2019, 13:32) | 40 |  99 % |
| Mods, Quads, Odds & Schröds by ThePedallingPianist (on 17. October 2023, 15:00) | 43 | 98 % |
| Delirium (Chaos Construction) by heliopolix (on 25. October 2024, 18:14) | 51 | 99 % |
| Carry the Three (two-digit arrow sudoku) by clover (on 30. October 2020, 18:10) | 29 | 97 % |
| Genome by Tyrgannus (on 7. July 2021, 21:33) | 42 | 97 % |
| Stingray (Killer Sudoku) by FryTheGuy (on 13. August 2021, 05:40) | 20 | 95 % |
| Build your own samurai sudoku by filuta (on 7. September 2021, 01:37) | 10 | 95 % |
| Chaos Construction: Thermos by XeonRisq (on 8. May 2022, 01:00) | 19 | 98 % |
| Three-legged Dog by Abdul the Killer (on 9. November 2022, 19:45) | 49 | 92 % |
| Trident by randall (on 6. January 2023, 23:46) | 18 | 95 % |
| Missing Digits by FryTheGuy (on 15. January 2023, 21:01) | 25 | 94 % |
| Japanese Sum Cave Cipher #12: Pentominous by KNT (on 26. January 2023, 04:41) | 40 | 99 % |
| Duplication by Xenonetix (on 28. July 2023, 00:00) | 36 | 98 % |
| Wichtel 2022 (6): Das Kleckskakuro by wichtel (on 4. October 2023, 13:13) | 18 | 98 % |
| Boxes of Paint (Colourful Killers) by The Book Wyrm (on 23. November 2023, 23:18) | 12 | 91 % |
| Does Phistomefel's Ring Still Apply? by bodemeister (on 23. February 2024, 08:43) | 18 | 98 % |
| Chaos Construction: 2nd Region Sight Sum (9x9) by Playmaker6174 (on 26. April 2024, 05:30) | 39 | 98 % |
| Bank Vault by mormagli (on 5. June 2024, 19:45) | 19 | 95 % |
| Factorial Cages by Nurator (on 13. August 2024, 10:48) | 12 | 90 % |
| Smelly Peas by MathGuy_12 (on 13. November 2025, 01:43) | 12 | 90 % |
