(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 | |
|---|---|---|---|
 | Code 9-12 (Sudoku31) by Sumanta(ANU) (on 18. July 2022, 15:39) | 31 |  92 % |
| Pianosa by jwsinclair (on 13. September 2022, 18:50) | 14 | 93 % |
| Jellyfish by Nordy (on 11. February 2023, 08:00) | 16 | 91 % |
| Treasure Torus by RaygunUltra (on 19. May 2024, 05:16) | 12 | 93 % |
| Spirality by Nordy (on 6. June 2024, 08:30) | 16 | 91 % |
| Gridunlocked (Tren Hybrid) by sfushidahardy (on 16. July 2024, 15:47) | 13 | 98 % |
| Recoil: A Proper Introduction by damasosos92 (on 17. March 2025, 18:09) | 37 | 95 % |
| Doppel-renbän-ger by Manta-Ray (on 6. December 2025, 14:34) | 32 | 94 % |
| Bridging The Mines by Florian Wortmann (on 7. December 2023, 20:20) | 206 | 96 % |
| Colorguru Chaos Deconstruction by crispy16 (on 30. May 2022, 03:09) | 52 | 97 % |
| Antiknight-Killer Sudoku - Fortyfour by X13579 (on 16. June 2020, 10:28) | 64 | 93 % |
| The Stinger by Mark Sweep (on 21. October 2020, 12:31) | 49 | 93 % |
| Set The Bar High by SimiC (on 7. January 2022, 10:20) | 27 | 99 % |
| Spaces in Between (Windoku Between Kropki X) by tallcat (on 8. May 2022, 17:17) | 79 | 95 % |
| Monster Muddle by Md88keys (on 29. August 2025, 07:04) | 31 | 91 % |
| Sharing is Caring (Twist on Renban Sudoku) by purpl (on 30. March 2022, 00:57) | 35 | 97 % |
| Tag 13 - Nurikabe by CJK (on 28. January 2021, 16:18) | 49 | 92 % |
| Contiguous by grkles (on 21. May 2022, 13:07) | 57 | 92 % |
| Rainbow Bricks by tsc (on 2. September 2022, 23:14) | 72 | 95 % |
| Sum Amount of Trouble by Tyrgannus (on 20. August 2023, 00:08) | 96 | 95 % |
