(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 | |
|---|---|---|---|
 | 2CT Appreciation (German Whispers thermometer sudoku) by Qodec (on 1. January 2024, 23:34) | 87 |  97 % |
| new year, who dis? by aqjhs (on 1. January 2025, 00:00) | 35 | 93 % |
| 3etweeN by Qodec (on 17. April 2021, 17:56) | 79 | 98 % |
| 3D JapaSumino + 3 by Luigi (on 6. December 2011, 20:25) | 45 | 98 % |
| 13 by Phurba (on 13. December 2020, 15:59) | 26 | 93 % |
| Palindrome Killer by MavericksJD (on 6. January 2021, 11:12) | 26 | 91 % |
| Cursed Quiver 2 (Region Sum Arrows CC) by Xendari (on 16. December 2022, 08:13) | 47 | 98 % |
| Pigeonhole [Renban, Kropki] by Miky (on 26. March 2023, 10:21) | 70 | 91 % |
| Oil Spill by Mayamor (on 20. April 2023, 14:35) | 27 | 92 % |
| Octopus Knight (Octopus Rules, Chess Lines) by gdc (on 10. June 2024, 15:51) | 24 | 93 % |
| Mehrdeutige Rätsel - Rundweg 2 by uvo (on 22. February 2017, 10:01) | 44 | 95 % |
| Gyroscope 3.0 by Ambrose (on 7. August 2022, 17:46) | 44 | 96 % |
| City of Skyscrapers by Kitty Trouble (on 5. November 2023, 14:45) | 39 | 96 % |
| RAT RUN 16: Schrödinger's Rat by marty_sears (on 27. November 2024, 01:00) | 426 | 98 % |
| 10-in-9 killer sudoku #4 by Nylimb (on 21. February 2020, 17:48) | 36 | 98 % |
| Six-pack Linked Puzzles by Genomico (on 17. September 2020, 00:51) | 57 | 97 % |
| Koralle (5) by Uhu (on 8. November 2020, 11:15) | 36 | 91 % |
| Qarpet Beater by Qodec (on 14. November 2020, 14:59) | 57 | 94 % |
| Silent Night by titus (on 18. December 2020, 02:06) | 25 | 90 % |
| Sandwich Cosmic Sudoku - Follow the North Galaxy by DiMono (on 27. December 2020, 21:37) | 18 | 93 % |
