(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 with Fillomino enclosures #3 (12x12) by Jesper (on 10. November 2024, 13:37) | 33 |  96 % |
| Chaos Construction: X-Sums / Sandwich by KNT (on 13. April 2022, 17:12) | 63 | 94 % |
| Kropki Magnetplatten III by tuace (on 12. January 2014, 07:30) | 31 | 99 % |
| Unique Values by Mesmer (on 25. January 2021, 12:20) | 70 | 98 % |
| Position Sums mit Renban-Streifen by glum_hippo (on 29. June 2021, 07:23) | 31 | 99 % |
| Dubai by Jay Dyer (on 7. March 2023, 22:49) | 35 | 94 % |
| Half Full Jar by Nimo (on 25. February 2025, 10:47) | 34 | 95 % |
| Ediacarium (Still Life Sudoku) by Qodec (on 12. October 2025, 18:37) | 35 | 94 % |
| [PAC] Cipher JS Clone Sudoku by TVDK (on 20. September 2025, 13:56) | 29 | 95 % |
| Half Life (Yin Yang Deconstruction) by Agent (on 30. August 2022, 09:00) | 84 | 99 % |
| X---V*4 by NurglesGift (on 11. April 2025, 06:00) | 92 | 96 % |
| Invisible Cages by Big Tiger (on 25. March 2021, 10:42) | 28 | 96 % |
| Houston by ICHTUES (on 5. September 2021, 06:00) | 25 | 92 % |
| Loop with a Coral Infestation by KNT (on 20. August 2023, 20:00) | 29 | 96 % |
| Pathfinder by vitaminz (on 10. June 2024, 20:50) | 30 | 99 % |
| Adventskalender 2023, Türchen 9 - Glashochhäuser by Zzzyxas (on 9. December 2023, 07:00) | 52 | 99 % |
| Pentomino Schleifen (NFF) by Richard (on 8. October 2010, 12:00) | 28 | 92 % |
| Palindrome Madness by SirWoezel (on 2. June 2020, 18:26) | 25 | 94 % |
| Sandwich Box by ademjaz (on 7. February 2023, 20:29) | 23 | 98 % |
| Tenuity (Japanese sums/Pentomino chain) by dumediat (on 14. September 2025, 15:03) | 25 | 100 % |
