(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 | |
|---|---|---|---|
 | Magic Clone Knight Sudoku by Rotstein (on 27. May 2020, 01:04) | 34 |  92 % |
| Irregular Sandbattle Sudoku (Starbattle vs. Sandwich) by Osh Tirola (on 14. June 2020, 15:00) | 31 | 97 % |
| Antiknight Whispers by thoughtbyte (on 12. February 2022, 08:58) | 31 | 90 % |
| Polychromatic by oklux (on 28. March 2022, 20:32) | 28 | 93 % |
| Bounds of Luck (Whisper MinMax) by tallcat (on 21. September 2022, 03:46) | 58 | 95 % |
| Guidance by Jagga (on 1. July 2023, 20:07) | 28 | 92 % |
| Tinsel Box by starwarigami (on 28. December 2023, 09:48) | 26 | 95 % |
| Aquanuradoku by Mennoo_ (on 6. March 2024, 21:33) | 56 | 90 % |
| Puzzle by usp (on 10. April 2015, 00:00) | 38 | 98 % |
| Nine Bent Arrows, One Straight by rmahus (on 14. March 2023, 10:00) | 43 | 97 % |
| Doublers Make Me Loop-Pea! by SamuPiano (on 9. September 2024, 15:44) | 34 | 93 % |
| Quantum Counting by gdc (on 17. November 2024, 13:39) | 48 | 95 % |
| The Quaker's Quiver by mathpesto (on 13. January 2025, 05:20) | 38 | 91 % |
| Sudoku Variants Series (224) - Sum or Product Frame Sudoku by Richard (on 13. March 2018, 00:00) | 99 | 92 % |
| Little Killer Killer Sudoku - Pinwheel by DiMono (on 27. October 2020, 23:51) | 55 | 94 % |
| Shade Some More Sum Lines by Xendari (on 23. August 2023, 07:51) | 51 | 98 % |
| DSM 2023 Leftover: Full Rank Sudoku by uvo (on 5. July 2023, 12:00) | 57 | 91 % |
| Leaning Tower Of ZooZ by Joseph nehme (on 7. January 2022, 18:47) | 95 | 96 % |
| Nothing is Wrogn by Jay Dyer (on 20. November 2022, 19:49) | 133 | 95 % |
| Hooked (Region Sum Lines) by Florian Wortmann (on 11. August 2024, 12:24) | 175 | 97 % |
