(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 | |
|---|---|---|---|
 | When It's Time To Parity We Will Parity Hard (with Calvinball) by ChinStrap (on 24. April 2025, 13:16) | 86 |  96 % |
| Box killer sudoku by udukos (on 20. August 2020, 11:06) | 71 | 97 % |
| Frak Redux (Ten Lines) by tallcat (on 25. October 2023, 09:00) | 61 | 95 % |
| Sompeo (Encaged Whispers) by ICHTUES (on 31. July 2022, 06:00) | 67 | 94 % |
| Zwei Rundwege aufeinander by Micha (on 31. December 2010, 16:04) | 46 | 98 % |
| Memphis by ICHTUES (on 20. February 2022, 06:00) | 52 | 95 % |
| Full House by juggler (on 20. June 2024, 01:17) | 105 | 97 % |
| The Quaker's Quiver by mathpesto (on 13. January 2025, 05:20) | 49 | 92 % |
| Ten-ish by ChinStrap (on 29. December 2025, 14:10) | 51 | 98 % |
| Cave Sudoku by Phistomefel (on 10. July 2020, 12:39) | 99 | 96 % |
| Tetrakiller by Jay Dyer (on 31. May 2022, 15:17) | 91 | 97 % |
| Noch ein runder Rundweg 2 by Calavera (on 11. August 2009, 18:09) | 41 | 98 % |
| Differenz X Kakuro IV (kryptisch) by tuace (on 31. August 2014, 21:30) | 42 | 97 % |
| Fifth Amendment (Killer Diagonal Sudoku) by Agent (on 4. March 2022, 09:00) | 45 | 96 % |
| Anti3sis (Yin Yang Doubler Sudoku) by Agent (on 8. November 2022, 09:00) | 87 | 98 % |
| Holy Water by wuc (on 26. March 2025, 17:29) | 57 | 93 % |
| 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 % |
