(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 | |
|---|---|---|---|
 | Uraninite (Killer cages, Odd/Even) by Bellsita (on 24. July 2024, 20:22) | 95 |  93 % |
| German Whispers Sandwich Sudoku by Jesper (on 4. July 2020, 11:47) | 81 | 96 % |
| RAT RUN 13: Triskaidekaphilia by marty_sears (on 6. November 2024, 02:13) | 647 | 97 % |
| Tetronimo Kakuro by julius64 (on 26. April 2013, 18:12) | 46 | 93 % |
| Toroidal Chess Sudoku #2 by Rotstein (on 7. June 2020, 20:24) | 26 | 92 % |
| 2X45 by Lisztes (on 22. October 2021, 01:00) | 28 | 92 % |
| WYSI by brandon_bot (on 18. June 2021, 07:27) | 27 | 94 % |
| Instructionless by Jesper (on 8. December 2021, 09:27) | 65 | 97 % |
| Sandbox Mode [Irregular RSL Sudoku] by wisty (on 24. May 2022, 17:36) | 23 | 91 % |
| Zahlen nach Malen / Numbers by paint by olima (on 10. June 2022, 16:16) | 22 | 93 % |
| Winded Arrows (Irregular Sudoku) by Aaronomys (on 22. August 2022, 05:18) | 23 | 97 % |
| Go Kart Race by zegres (on 12. September 2023, 08:19) | 47 | 91 % |
| Croque Madame by Black_Doom (on 14. April 2024, 17:07) | 25 | 96 % |
| Thermal Counting Quads by MSDOS (on 28. June 2024, 02:51) | 32 | 94 % |
| Tri-Colour Coaster #1 by ClashCode (on 11. June 2025, 04:55) | 21 | 91 % |
| Dutch Flat Mates (Dorminoes) by Black_Doom (on 23. July 2025, 11:30) | 55 | 95 % |
| Sudoku Variants Series (275) - Confetti Sums Sudoku by Richard (on 1. July 2020, 00:00) | 108 | 98 % |
| XY-Differences Fillomino by glum_hippo (on 21. August 2023, 01:39) | 58 | 97 % |
| Moooooo by ademjaz (on 20. May 2024, 18:10) | 115 | 97 % |
| Lion-Fish (Killer Sudoku) by abed hawila (on 6. March 2021, 18:51) | 92 | 96 % |
