(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 | |
|---|---|---|---|
 | Roller Coaster mit Extras 13 by Uhu (on 21. March 2019, 22:34) | 51 |  99 % |
| Field Lines by mathpesto (on 8. April 2023, 21:10) | 102 | 98 % |
| Chaos II: The Two Killers by lerroyy (on 18. April 2022, 22:25) | 51 | 98 % |
| Throne Room (Sudokuvania boss) by SkepticalMario (on 20. June 2025, 07:07) | 64 | 96 % |
| Little Thermo Killer by Jesper (on 19. June 2020, 23:30) | 61 | 96 % |
| X-Sums killer sudoku #2 by udukos (on 10. October 2022, 21:08) | 60 | 98 % |
| Nurimisaki Killer by Jay Dyer (on 27. March 2023, 18:51) | 58 | 98 % |
| Parity Party VII — "Party Sandwiches" by glum_hippo (on 25. April 2020, 23:24) | 21 | 94 % |
| Tag 24 - Finale by CJK (on 20. February 2021, 14:48) | 46 | 97 % |
| Paulas Geheimschrift-Rundweg-Puzzle by CJK (on 19. April 2021, 10:27) | 26 | 100 % |
| Parity Party XIX, "Kryppto" by glum_hippo (on 10. June 2021, 17:06) | 28 | 100 % |
| Hendiadyoin Sudoku by ICHTUES (on 17. October 2021, 06:00) | 23 | 94 % |
| Four body problem by filuta (on 21. November 2021, 18:11) | 13 | 92 % |
| Exactly Eighty by krangune (on 23. January 2022, 17:08) | 51 | 97 % |
| Chaosandwich by grkles (on 11. April 2022, 19:24) | 82 | 100 % |
| Biagonal Bichael (Chaos Construction) by purpl (on 29. May 2022, 17:32) | 36 | 98 % |
| The Unlikely Duos - A 6-pack Linked Sudokus Puzzle by Playmaker6174 (on 8. June 2022, 01:50) | 25 | 99 % |
| Hey, Are You Awake? by mathpesto (on 7. August 2022, 22:06) | 39 | 98 % |
| Coordinated Killers by Samish (on 11. September 2022, 09:09) | 63 | 96 % |
| Hook, Line and Sinker by SenatorGronk (on 29. September 2022, 00:21) | 19 | 92 % |
