(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 | |
|---|---|---|---|
 | MENSCH - Buchstabenrätsel / Letter Puzzle by DocLogic (on 12. June 2024, 16:35) | 21 |  95 % |
| Post von den Außerirdischen by ibag (on 6. September 2014, 06:09) | 31 | 97 % |
| Dislocation by Ali M (on 26. July 2023, 22:58) | 75 | 92 % |
| Vampires by grkles (on 22. October 2021, 02:12) | 43 | 98 % |
| Yin Yang Vaults by Schwupel (on 1. September 2022, 22:19) | 48 | 97 % |
| Japanisches Summen-Masyu by Uhu (on 20. June 2017, 17:56) | 48 | 99 % |
| First Hidden Skyscraper Sudoku (Full Odd) by Feadoor (on 11. February 2020, 15:42) | 41 | 97 % |
| Gaelic Knot by cam (on 27. September 2020, 20:08) | 14 | 93 % |
| Killer sudoku: Noughts and Crosses by Martijn (on 5. October 2020, 12:07) | 15 | 90 % |
| Die Bahn ist auch auf dem Zylinder pünktlich ... by ibag (on 17. February 2021, 23:58) | 10 | 98 % |
| Pointing Pairs Fillomino by Mark Sweep (on 16. April 2021, 10:00) | 25 | 98 % |
| Even Numbers are Social Distancing by swaroop2012 (on 3. May 2021, 21:15) | 13 | 90 % |
| Stingray by zetamath (on 23. June 2021, 19:36) | 38 | 92 % |
| Mixed Doubles by Scruffamudda (on 4. November 2021, 23:37) | 11 | 98 % |
| Suguru Chaos Deconstruction: Quadruples by Niverio (on 3. May 2022, 12:39) | 86 | 98 % |
| Earthworm City (Killer + Renban Sudoku) by Sktx (on 17. August 2022, 10:57) | 12 | 98 % |
| Cyclone by antiknight (on 2. September 2022, 04:07) | 28 | 90 % |
| Competitive Tetris by Bremster (on 23. September 2022, 09:00) | 52 | 94 % |
| Equivocation by SSG (on 27. September 2022, 07:02) | 35 | 97 % |
| Position Sums Fillomino #3: Internal Clues by ONeill (on 26. October 2022, 12:59) | 24 | 100 % |
