(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 | |
|---|---|---|---|
 | The Edge of Reason by Abdul the Killer (on 7. May 2024, 12:34) | 23 |  93 % |
| Bittersweet Candies 4 - A (Mostly) Regular 6x6 Sudoku Pack (reworked) by Playmaker6174 (on 22. May 2024, 01:30) | 20 | 98 % |
| Loopy Whisper 'Wich by yttrio (on 24. May 2024, 21:47) | 40 | 96 % |
| Foggy Pea-losophy by SamuPiano (on 2. November 2024, 15:44) | 133 | 97 % |
| Chameleon [Antiknight Series] by wisty (on 26. November 2024, 15:35) | 69 | 91 % |
| Cheryl's Sudoku by Elytron (on 3. June 2025, 03:50) | 166 | 96 % |
| Sidereal nebulae by NicoD (on 18. July 2025, 05:30) | 25 | 91 % |
| daft zebras jump quickly by aqjhs (on 28. November 2025, 01:23) | 26 | 92 % |
| House of Cards (6x6) by jwsinclair (on 14. December 2025, 23:17) | 47 | 93 % |
| Counting Thermos by Scojo (on 17. December 2023, 21:16) | 126 | 97 % |
| YZ - XV by Scruffamudda (on 16. May 2023, 03:02) | 75 | 95 % |
| Terracotta Kids (Anti-Knight, German Whisper, Renban, Kropki) by juddimal (on 2. August 2025, 06:14) | 87 | 95 % |
| Cageless (X) Killer Sudoku by Shinya (on 13. March 2020, 17:26) | 60 | 99 % |
| Ambiguous Slitherlink by Agent (on 28. April 2024, 09:00) | 58 | 98 % |
| Ominous Yajilin by Jay Dyer (on 23. June 2024, 21:12) | 52 | 95 % |
| Primal Instinct (Killer Sudoku) by Agent (on 25. July 2023, 09:00) | 165 | 97 % |
| Holographic Principle (Chaos Construction) by sfushidahardy (on 18. July 2024, 04:07) | 215 | 98 % |
| Quadrilateral by jwsinclair (on 20. April 2024, 18:03) | 104 | 98 % |
| 1000 Rooms by Qodec (on 10. May 2022, 22:37) | 44 | 94 % |
| Numbered Corridors by RockyRoer (on 7. July 2022, 13:25) | 48 | 97 % |
