(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 | |
|---|---|---|---|
 | Hallig-Rundreise by tuace (on 13. April 2015, 00:47) | 41 |  100 % |
| There is still life in my sandwich... by Sktx (on 15. May 2021, 00:49) | 14 | 94 % |
| Friendly X-Sums (Chaos Construction) by thoughtbyte (on 16. July 2022, 23:11) | 29 | 100 % |
| Trimodi (Modifier Entropy) by Mad-Tyas (on 10. January 2023, 00:48) | 15 | 94 % |
| Killocator: Dead or Alive by starwarigami (on 28. February 2024, 10:17) | 14 | 96 % |
| Arrow/Group Sum Sudoku by ahaupt (on 10. July 2020, 21:53) | 60 | 99 % |
| Sandwich Sudoku by kolot (on 15. July 2021, 18:33) | 30 | 95 % |
| Japanese Sum Nurikabe #2 (16x16) by KNT (on 6. September 2022, 02:52) | 52 | 100 % |
| Palindromic Little Killer X Sudoku by SudokuExplorer (on 23. February 2021, 01:00) | 43 | 96 % |
| Invisible Thermometers by Nahileon (on 17. May 2023, 12:51) | 44 | 93 % |
| Außerirdische Krypto Killer Pyramide by tuace (on 30. April 2014, 20:00) | 23 | 99 % |
| Das Prinzip der Polarität by tuace (on 3. September 2017, 17:16) | 24 | 96 % |
| 4D Arrow Sudoku by FryTheGuy (on 6. July 2021, 11:20) | 12 | 98 % |
| Archery Target by Nahileon (on 24. April 2022, 15:48) | 38 | 97 % |
| Entropic Loop Chaos by yttrio (on 9. February 2024, 19:28) | 65 | 96 % |
| Gin (11x11 Deconstruction) by lerroyy (on 13. November 2022, 23:51) | 23 | 99 % |
| Wichtel 2017 (8): Ein rätselhaftes Experiment by wichtel (on 17. August 2018, 03:05) | 33 | 100 % |
| Wave Particles by TotallyNormalCat (on 22. April 2021, 19:00) | 52 | 99 % |
| Aquatic Construction (9x9) by KNT (on 23. June 2022, 01:08) | 53 | 100 % |
| Chaotic Wrogn [Tribute to DiMono] by Undar_Beyond (on 28. December 2020, 08:14) | 77 | 99 % |
