(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 | |
|---|---|---|---|
 | 10-in-9 calcudoku #3 (2021) by Nylimb (on 1. January 2021, 00:00) | 25 |  96 % |
| Kite Setting by thoughtbyte (on 22. August 2021, 19:40) | 28 | 96 % |
| Locked Outside by MavericksJD (on 30. September 2021, 00:00) | 29 | 91 % |
| Close Friends II by mathpesto (on 24. December 2021, 07:06) | 28 | 91 % |
| Rectangles by Sktx (on 19. February 2022, 13:08) | 24 | 95 % |
| Radar by Jobo (on 10. August 2023, 09:48) | 82 | 93 % |
| EntROPEy by Mad-Tyas (on 2. May 2024, 05:47) | 28 | 95 % |
| Black or White Coral by KNT (on 27. May 2024, 03:47) | 51 | 98 % |
| Tri-Colour Coaster #1 by ClashCode (on 11. June 2025, 04:55) | 22 | 91 % |
| Blue Sticks by antiknight (on 26. July 2025, 01:49) | 25 | 90 % |
| 2D Printer (Pentomino + Loop) by sfushidahardy (on 17. September 2025, 18:29) | 25 | 99 % |
| Even Arrows by juggler (on 5. May 2026, 04:01) | 54 | 96 % |
| Dark City (skyscraper cave with fog) by SkepticalMario (on 30. November 2024, 11:11) | 75 | 92 % |
| Hinges by jovi_al (on 20. December 2021, 02:37) | 135 | 98 % |
| Auf dem Oktoberfest by pirx (on 21. September 2013, 12:00) | 36 | 99 % |
| A BAD IDEA by PrimeWeasel (on 31. January 2021, 12:10) | 18 | 97 % |
| X-Sums Fillomino #3 (4x4x4) by Jesper (on 15. March 2021, 19:53) | 43 | 100 % |
| Pentominous sandwich sudoku by Nylimb (on 28. April 2021, 17:11) | 20 | 97 % |
| Thermal Killer (frei nach Madmahogany) by glum_hippo (on 6. May 2021, 05:30) | 44 | 93 % |
| Introducing Anchor Sudoku! by FryTheGuy (on 8. June 2021, 16:48) | 25 | 94 % |
