(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 | |
|---|---|---|---|
 | Whose Line is it Anyway? (Region Sum, Renban, Global Entropy) by Chefofdeath (on 16. June 2024, 18:21) | 38 |  93 % |
| Es war einmal eine geheime Schrift by berni (on 1. November 2008, 15:56) | 78 | 92 % |
| Neulich beim Stammtisch Ruhrgebiet by berni (on 15. December 2013, 15:28) | 46 | 97 % |
| Broken Slitherlink by ahaupt (on 21. May 2020, 11:02) | 53 | 99 % |
| Shoot the Pears by tallcat (on 9. April 2021, 15:50) | 49 | 96 % |
| Four Sevens by ThePedallingPianist (on 8. December 2022, 19:53) | 28 | 91 % |
| Circle Squared by Ridhwan (on 2. January 2024, 03:27) | 31 | 96 % |
| Gravitation by Niverio (on 3. July 2024, 19:49) | 25 | 92 % |
| Homebound Sandwich Sudoku by Sebastian Losch (on 25. April 2020, 21:37) | 19 | 94 % |
| Gossiping Queens on 7x7 Torus by SudokuExplorer (on 10. September 2020, 17:44) | 17 | 93 % |
| Sandwich Sudoku--春卷 by cdwg2000 (on 30. October 2020, 13:56) | 18 | 91 % |
| Mystery Sandwiches or X-Sums by UnnamedSorcerer (on 18. November 2020, 01:59) | 15 | 96 % |
| Killer Quiver by MrMercurial (on 4. December 2020, 05:20) | 61 | 91 % |
| Triplet Sums by Realshaggy (on 27. January 2021, 23:59) | 30 | 93 % |
| The BremSter Thermo Conundrum by Zombie Hunter (on 16. September 2021, 00:25) | 19 | 92 % |
| T Time by EricRathbun (on 23. March 2022, 21:44) | 32 | 97 % |
| Prime Directive by DiMono (on 15. April 2023, 15:35) | 15 | 92 % |
| Modular Loop by SamuPiano (on 8. November 2023, 05:29) | 13 | 94 % |
| Maria by dennischen (on 9. March 2024, 06:46) | 54 | 90 % |
| Gerade-Ungerade-Killer III by Realshaggy (on 17. September 2013, 11:31) | 84 | 95 % |
