(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 | |
|---|---|---|---|
 | Kuromasudoku by Phistomefel (on 26. November 2020, 20:18) | 81 |  99 % |
| Die Kryptos - S03E05: Spiral City Construction by tuace (on 30. October 2018, 10:14) | 50 | 98 % |
| Food Killer by Mark Sweep (on 27. November 2020, 10:00) | 25 | 98 % |
| The Disjointed Cube by Wecoc (on 8. January 2021, 01:57) | 58 | 96 % |
| Classic-style Killer Sudoku by Jeet Sampat (on 27. January 2022, 22:59) | 35 | 95 % |
| Sum Hope (Sum Lines) by Chilly (on 26. April 2022, 11:23) | 50 | 97 % |
| MP: Region Sum Lines Fillomino by Myxo (on 28. January 2023, 14:28) | 47 | 98 % |
| Death Stare by Die Hard (on 5. February 2023, 21:21) | 28 | 93 % |
| Tetris Ain't In My Genes by Groktilian (on 3. October 2023, 16:00) | 30 | 93 % |
| Ring of Fire by lmdemasi (on 18. December 2023, 15:55) | 57 | 94 % |
| Club 27 (Thermo Sudoku) by Blashyrkh (on 22. March 2024, 22:12) | 96 | 99 % |
| Molopo (XY-Differences Sudoku) by Qodec (on 29. March 2024, 15:34) | 75 | 95 % |
| pollux by aqjhs (on 1. February 2025, 00:00) | 24 | 96 % |
| Campground by Oripy (on 24. March 2025, 12:23) | 21 | 95 % |
| Big ol' arrow (deconstruction) by graggle (on 13. September 2025, 11:00) | 24 | 95 % |
| Brasero by NicoD (on 23. September 2025, 05:30) | 33 | 93 % |
| Killer Pairs (Black) by Yawnus (on 26. April 2026, 12:30) | 23 | 95 % |
| Scientific Method (Killer) by tallcat (on 5. March 2022, 04:46) | 91 | 97 % |
| Project 37 by Blashyrkh (on 6. December 2023, 13:48) | 75 | 93 % |
| Schlangen im Fillomino-Nest II by tuace (on 3. March 2017, 11:24) | 36 | 99 % |
