(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 | |
|---|---|---|---|
 | Bounce by zetamath (on 25. April 2022, 16:17) | 54 |  99 % |
| Killer Sudomino (Killer Sudoku+Fillomino Hybrid) by AnalyticalNinja (on 31. October 2022, 14:08) | 49 | 98 % |
| A New Secret by blackjackfitz (on 6. February 2023, 19:05) | 15 | 98 % |
| Nestification Jigsaw by Lyun Licuss (on 28. February 2023, 17:15) | 19 | 100 % |
| Amaterasu [Thermo Sudoku] by wisty (on 27. March 2023, 10:15) | 33 | 90 % |
| Little Killer Irrwisch Sudoku by clover (on 23. December 2023, 15:53) | 15 | 92 % |
| Overdose by XeonRisq (on 20. February 2024, 23:00) | 29 | 91 % |
| polyline polyglot by aqjhs (on 3. March 2025, 17:40) | 13 | 90 % |
| Impossible Germany by Neokart (on 28. October 2024, 02:41) | 32 | 96 % |
| Cipher JS(Aqre) Sudoku by Las4one (on 25. September 2025, 03:10) | 15 | 94 % |
| Privy (German Whispers/Renban/Sandwich) by dumediat (on 24. April 2023, 14:06) | 61 | 95 % |
| Miami by zetamath (on 28. May 2023, 20:49) | 59 | 100 % |
| Thou Shalt Pass by Wuschel (on 3. February 2025, 09:39) | 56 | 98 % |
| LM-Überbleibsel: Krypto-Teamrunde by uvo (on 28. November 2015, 10:00) | 76 | 99 % |
| Killer Numbered Rooms by the_cogito (on 21. March 2023, 21:04) | 38 | 95 % |
| New York City by ICHTUES (on 30. April 2025, 07:50) | 128 | 97 % |
| Hakyuu-Hitori Kombi by pwahs (on 28. June 2011, 11:36) | 49 | 97 % |
| Vers la Flamme by Piatato (on 17. May 2021, 20:39) | 47 | 95 % |
| Chaos Construction - Oenopion's Return by Niverio (on 31. May 2023, 22:18) | 104 | 97 % |
| Re(cursive/entry) by mormagli (on 25. June 2024, 21:03) | 25 | 95 % |
