(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 | |
|---|---|---|---|
 | Candy Corner (ft. grkles) by Niverio (on 10. November 2023, 18:53) | 38 |  92 % |
| Balanced U-Bahn [Cave U-Bahn] by wisty (on 24. February 2025, 21:06) | 17 | 98 % |
| [PAC] Triple Japanese Sums by The Book Wyrm (on 24. October 2025, 19:01) | 33 | 99 % |
| U-Bahn Inception by Agent (on 28. February 2026, 09:00) | 21 | 98 % |
| Fill Rank Fullomino by Myxo (on 31. May 2023, 13:26) | 63 | 98 % |
| LM 2017 Reste: Achterbahn (ohne Sicherheitsgurte) by pwahs (on 14. April 2017, 10:00) | 36 | 99 % |
| Obvious Killer by filuta (on 29. March 2021, 11:31) | 34 | 97 % |
| Double the Heat by Jay Dyer (on 17. September 2022, 21:55) | 39 | 99 % |
| Chaotic Wrogn [Tribute to DiMono] by Undar_Beyond (on 28. December 2020, 08:14) | 102 | 97 % |
| Enantiodromia (Yin-Yang Chaos Construction, 8x8) by thoughtbyte (on 3. August 2022, 00:05) | 28 | 99 % |
| Sudoku O.W.L. by Nahileon (on 10. October 2022, 21:25) | 25 | 100 % |
| Lost City (Lost and Found #7) by .proxz14 (on 26. April 2025, 10:00) | 28 | 93 % |
| Kurotto Killer Sudoku by KNT (on 29. July 2022, 04:21) | 75 | 95 % |
| Palindromic Little Killer X Sudoku by SudokuExplorer (on 23. February 2021, 01:00) | 52 | 95 % |
| Summation U-Bahn #4: Skyscrapers by Agent (on 30. September 2024, 09:00) | 44 | 100 % |
| Sadism by grkles (on 17. October 2022, 13:05) | 58 | 96 % |
| Odd one out by jenssteenmetz (on 26. June 2021, 23:06) | 18 | 100 % |
| Syzygy Stardust by David BOWie by mith (on 11. April 2022, 21:48) | 42 | 97 % |
| Trimodi (Modifier Entropy) by Mad-Tyas (on 10. January 2023, 00:48) | 20 | 95 % |
| Sandwich gone BAD by PrimeWeasel (on 3. March 2023, 17:59) | 15 | 98 % |
