(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 | |
|---|---|---|---|
 | Oklahoma City by ICHTUES (on 27. November 2022, 06:00) | 60 |  96 % |
| Zum Geburtstag by Uhu (on 5. March 2017, 10:24) | 37 | 99 % |
| Disjoint Little Killer Sudoku - 89 Spinning Tops by DiMono (on 6. December 2020, 18:50) | 19 | 95 % |
| Disjoint X Arrows by Mesmer (on 15. October 2021, 20:44) | 12 | 90 % |
| Kashmir by lerroyy (on 29. March 2022, 20:26) | 50 | 96 % |
| Mercurial Maxima by AFrayedKnot (on 13. June 2022, 17:59) | 17 | 100 % |
| El Psy Kongroo by lerroyy (on 21. July 2022, 04:00) | 35 | 97 % |
| Double Negative by DadJokes (on 4. October 2022, 13:35) | 17 | 90 % |
| The Turtle (Renban, Entropy) by Mad-Tyas (on 28. March 2023, 09:21) | 36 | 98 % |
| Squares with Chaotic Circles by thoughtbyte (on 18. January 2024, 09:07) | 41 | 99 % |
| Killer Sudoku by ahaupt (on 30. June 2020, 12:15) | 52 | 96 % |
| Snack'O'Mino [Level #2] by Christounet (on 9. March 2023, 12:47) | 46 | 100 % |
| Melancholia (Build your own arrow) by Sartor (on 15. June 2024, 23:05) | 44 | 99 % |
| Build Your Own Sloop by Piatato (on 5. July 2023, 21:23) | 34 | 99 % |
| The Elephant (Renban, Entropy) by Mad-Tyas (on 3. January 2023, 11:37) | 33 | 99 % |
| Renban-na-na-na-na-na by SirSchmoopy (on 18. March 2022, 02:30) | 22 | 100 % |
| Quantum Whispers by tesseralis (on 17. July 2022, 01:09) | 21 | 100 % |
| Three-legged Dog by Abdul the Killer (on 9. November 2022, 19:45) | 46 | 93 % |
| Dante's Chaotic Journey by SenatorGronk (on 7. July 2023, 04:16) | 22 | 100 % |
| German Whisper Cages by kolot (on 17. March 2022, 19:50) | 60 | 98 % |
