(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 | |
|---|---|---|---|
 | DoppLKänger by ChinStrap (on 2. December 2025, 18:59) | 53 |  98 % |
| More Unique Arrows by Jolly Rogers (on 28. December 2025, 11:51) | 80 | 95 % |
| Cycles of Time and Tide by zetamath (on 6. July 2025, 00:38) | 124 | 96 % |
| Sudoku Variants Series (302) - Y-Sums Sudoku by Richard (on 6. January 2021, 00:00) | 106 | 97 % |
| Raw Spaghetti (equal sums lines sudoku) by Aspartagcus (on 23. June 2022, 23:19) | 71 | 97 % |
| Huitzilopochtli by aqjhs (on 25. December 2024, 13:07) | 77 | 95 % |
| A Bigger Squish by marty_sears (on 18. December 2023, 17:35) | 53 | 95 % |
| Japanische Summen mit Querverweisen by ibag (on 23. December 2011, 21:31) | 72 | 98 % |
| U-Bahn unter Hochhäusern (Teil 4) by Zzzyxas (on 31. March 2012, 16:17) | 76 | 97 % |
| Killer Sudoku by Greg (on 14. June 2020, 21:04) | 42 | 92 % |
| Pandora's BoXXX by twototenth (on 13. December 2022, 08:00) | 43 | 94 % |
| Switch-O-Renban by Ridhwan (on 5. May 2024, 11:06) | 38 | 95 % |
| Incongruity by zetamath (on 20. August 2024, 20:36) | 45 | 96 % |
| Rank Up 20.jv - Mod 3 by vitaminz (on 10. October 2025, 14:58) | 38 | 91 % |
| CtC-Tribute-Thermo-Sudoku by olima (on 15. August 2020, 23:42) | 63 | 91 % |
| Thermo X Sudoku by Phistomefel (on 2. December 2020, 20:08) | 155 | 93 % |
| # (Arrow Sudoku) by Cane_Puzzles (on 4. June 2021, 17:00) | 26 | 97 % |
| Revolution by Stavros96 (on 18. September 2021, 10:54) | 30 | 97 % |
| A Little Deconstruction by djorr (on 14. April 2022, 14:00) | 29 | 93 % |
| Time to Think Outside the Box by zegres (on 1. March 2022, 06:49) | 56 | 98 % |
