(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 | |
|---|---|---|---|
 | Min-Max-Sichtblöcke (4) by BFaw (on 14. December 2016, 10:00) | 20 |  94 % |
| Odd River - Prime Whispers Sudoku by ibn Muhyiddin (on 20. July 2020, 14:43) | 20 | 99 % |
| Gordian Knot by Joseph nehme (on 3. March 2021, 16:20) | 55 | 97 % |
| Stairway to Heaven (collaboration with purpl) by TheRiddler (on 15. October 2021, 17:54) | 27 | 97 % |
| X-Sum Clues in the Grid by kolot (on 8. November 2021, 05:19) | 23 | 96 % |
| Smallhat by the_cogito (on 21. April 2022, 17:27) | 55 | 96 % |
| Tower Construct by Xenonetix (on 17. June 2022, 21:00) | 36 | 98 % |
| Consecutive Sudoku by AstralSky (on 28. November 2022, 18:01) | 40 | 92 % |
| The Hot Squeeze by meggen033 (on 31. January 2023, 07:59) | 31 | 90 % |
| BAUERNHOF - 3D-Buchstabenrätsel / 3D letter puzzle by DocLogic (on 24. July 2023, 15:15) | 32 | 97 % |
| Smoggy King? by MathGuy_12 (on 14. May 2025, 02:13) | 32 | 90 % |
| the herding party by aqjhs (on 8. October 2025, 05:32) | 20 | 94 % |
| Copycat Scratch Fever (with ChinStrap) by Calvinball (on 9. May 2026, 05:09) | 20 | 99 % |
| XV*Roundabout by NurglesGift (on 14. March 2025, 08:00) | 123 | 95 % |
| Lattice by pieguy (on 26. January 2023, 18:43) | 70 | 98 % |
| Algebra 101 (Cipher X-Sum) by tallcat (on 29. April 2023, 09:00) | 40 | 95 % |
| Two Truths and a Different Truth by Oddlyeven (on 15. September 2025, 00:09) | 82 | 97 % |
| Neue Post vom Außerirdischen by ibag (on 6. September 2015, 00:00) | 62 | 100 % |
| [Fog of War Series] 2.Interlinked by AstralSky (on 26. October 2022, 04:36) | 73 | 91 % |
| Xerox by MathGuy_12 (on 22. February 2026, 17:45) | 64 | 94 % |
