(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 | |
|---|---|---|---|
 | Parity Clockwork by Playmaker6174 (on 20. January 2022, 20:24) | 51 |  96 % |
| /4 /5 by Nahileon (on 18. March 2022, 11:03) | 59 | 99 % |
| Discombobulation by NicoD (on 9. May 2025, 05:30) | 124 | 98 % |
| This is it. I've done it. by EricRathbun (on 23. April 2023, 00:19) | 60 | 97 % |
| Inception by Joseph nehme (on 8. May 2021, 07:42) | 65 | 96 % |
| Whispering Chaos by 72kchunshuai (on 1. February 2026, 12:00) | 76 | 94 % |
| RiesenRenbanKropki by Richard (on 26. March 2010, 12:00) | 71 | 90 % |
| Renban -Kakuro 1-10 / 2 by julius64 (on 4. May 2011, 21:18) | 68 | 94 % |
| Chaos 12 (Chaos Construction) by MaizeGator (on 19. May 2025, 03:30) | 79 | 98 % |
| Sudoku Variants Series (362) - Star Sums Sudoku by Richard (on 9. March 2022, 00:00) | 81 | 95 % |
| Rundweg auf der Kleinschen Flasche by flooser (on 14. November 2009, 12:52) | 54 | 91 % |
| Lasersummen (3) by BFaw (on 20. January 2012, 20:10) | 32 | 95 % |
| Adventsportale, Teil 2 by pirx (on 9. December 2018, 12:00) | 34 | 97 % |
| "Incomplete" Killer Sudoku by Greg (on 12. June 2020, 01:55) | 25 | 90 % |
| Battlefield Sudoku - Ring Theory by DiMono (on 4. July 2020, 23:21) | 32 | 90 % |
| Yajilin Sudoku by Madmahogany (on 19. July 2020, 12:39) | 35 | 94 % |
| Whodunit by Djmelee3000 (on 11. August 2020, 00:56) | 27 | 93 % |
| Pentomino Loop Sudoku by Quarterthru (on 5. November 2020, 12:00) | 28 | 94 % |
| 9 Cages by PrimeWeasel (on 30. November 2020, 15:57) | 25 | 90 % |
| The Key by jetalix (on 8. January 2021, 20:02) | 28 | 98 % |
