(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 | |
|---|---|---|---|
 | Anti3sis (Yin Yang Doubler Sudoku) by Agent (on 8. November 2022, 09:00) | 87 |  98 % |
| Dutch Fillomino Mates by mathpesto (on 10. April 2025, 22:32) | 48 | 99 % |
| Fillomino Whispers by Die Hard (on 25. April 2025, 04:11) | 49 | 96 % |
| Zodiac Project: Gemini by Christounet (on 19. September 2024, 13:18) | 126 | 98 % |
| Glass Numbered Rooms by Xenonetix (on 27. April 2022, 01:23) | 74 | 99 % |
| Little Killer Sudoku by Philipp Huber (on 5. July 2020, 13:02) | 36 | 91 % |
| Diagonal Skyscraper Sudoku by MagnusJosefsson (on 15. April 2021, 16:32) | 40 | 96 % |
| Killed Bulbs and Killer Cages - Thermo(?) Killer Sudoku by Cane_Puzzles (on 18. April 2021, 13:30) | 41 | 96 % |
| Good Luck, Bad Luck by oberon (on 21. February 2022, 20:29) | 46 | 97 % |
| Domino Fever (Entropy Edition) by Mad-Tyas (on 21. February 2022, 23:32) | 75 | 94 % |
| Digital Sandwich by Prof.Dori (on 30. May 2023, 21:35) | 32 | 95 % |
| Ripples by riffclown (on 4. August 2023, 21:59) | 75 | 96 % |
| Memento Regem by LeaVulpina (on 10. March 2024, 00:23) | 35 | 93 % |
| Infantapaulting Hypothesis (Slingshot Nurikabe) by sfushidahardy (on 17. August 2025, 01:47) | 40 | 100 % |
| Squishdoku by Jay Dyer (on 21. November 2023, 00:36) | 104 | 95 % |
| Sudoku Variants Series (288) - Battlefield Sudoku by Richard (on 30. September 2020, 00:00) | 69 | 97 % |
| Kyushu by AFrayedKnot (on 9. November 2024, 07:52) | 63 | 99 % |
| Tetrakiller by Jay Dyer (on 31. May 2022, 15:17) | 90 | 97 % |
| Wichtel 2019 (10): Die Wohnquartiere der Wichtel by wichtel (on 2. November 2020, 19:20) | 52 | 100 % |
| Dude where's my XV? by PetLov (on 6. February 2021, 21:06) | 33 | 92 % |
