(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 | |
|---|---|---|---|
 | Happy Birthday Piatato: A Doppelblock U-Bahn by wisty (on 30. August 2023, 03:33) | 38 |  99 % |
| Sudoku Variants Series (323) - Killer Kropki Sudoku by Richard (on 2. June 2021, 00:00) | 78 | 96 % |
| Sakurairo [Pencilmark Sudoku] by wisty (on 24. February 2023, 03:45) | 36 | 93 % |
| Zombie! (Araf + Yin-Yang) by sfushidahardy (on 13. April 2025, 17:06) | 63 | 96 % |
| Chiaroscuro U-Bahn by yttrio (on 17. May 2025, 01:40) | 31 | 95 % |
| Made in the Shade (Heyawake CC) (w/ SennyK) by mellowrobinson (on 3. February 2026, 17:49) | 40 | 99 % |
| Japanese Sums with Arrows by mathpesto (on 31. December 2021, 22:24) | 41 | 95 % |
| JCQ #5: Fawlty Towers (Liar Thermo Killer Sudoku) by peterchayward (on 17. July 2020, 11:13) | 57 | 96 % |
| Myriad of Triad by Tyrgannus (on 18. April 2021, 22:04) | 32 | 94 % |
| A Latin Earthquake by PrimeWeasel (on 15. April 2022, 22:56) | 20 | 97 % |
| Akamata by Jay Dyer (on 10. June 2024, 21:55) | 25 | 90 % |
| The 15-Box Odyssey by Duarte-Carvalho (on 11. October 2025, 10:00) | 38 | 91 % |
| Chinmax Skystrappers by ChinStrap (on 30. May 2025, 18:04) | 58 | 94 % |
| Border Count Pentominous by Gliperal (on 13. March 2023, 00:08) | 37 | 92 % |
| Building Regions in Fog of War: Border Patrol 1 by Jeet Sampat (on 23. March 2024, 17:59) | 45 | 91 % |
| Productivity Killer by starwarigami (on 13. January 2024, 21:02) | 27 | 92 % |
| Chaos Construction: Disconnected (2) by KNT (on 20. May 2024, 04:09) | 88 | 98 % |
| Thermos Construction by Prof.Dori (on 15. December 2023, 02:00) | 62 | 92 % |
| Wichtel 2021 (2): Der Sternenkompass by wichtel (on 1. June 2022, 21:20) | 16 | 93 % |
| LM-Übungsrätsel: No Same Sums by CJK (on 1. July 2023, 20:23) | 16 | 96 % |
