(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 | |
|---|---|---|---|
 | Spaces in Between (Windoku Between Kropki X) by tallcat (on 8. May 2022, 17:17) | 70 |  95 % |
| Entropy and Whispers (Sudoku29) by Sumanta(ANU) (on 16. June 2022, 14:34) | 47 | 94 % |
| Don't Touch by Scruffamudda (on 28. June 2022, 07:54) | 15 | 92 % |
| The Square Wheel by EricRathbun (on 21. August 2022, 16:26) | 25 | 92 % |
| Skyscraper Index by jwsinclair (on 11. July 2022, 19:32) | 12 | 96 % |
| Die Kryptos - S05E03: Mathrax by tuace (on 1. September 2022, 20:22) | 21 | 91 % |
| Speed Up by ademjaz (on 6. October 2022, 11:04) | 46 | 96 % |
| Wheat, Oats and Poppy by jcgodart (on 15. October 2022, 08:19) | 19 | 93 % |
| SINIS by ICHTUES (on 16. October 2022, 06:00) | 31 | 95 % |
| Arrow Bites by PotatoHead21 (on 30. October 2022, 21:57) | 17 | 98 % |
| Unique Duo by sujoyku (on 16. November 2022, 20:56) | 22 | 92 % |
| The Violin by XeonRisq (on 21. December 2022, 19:00) | 17 | 96 % |
| Spindrift by SeveNateNine (on 1. January 2023, 02:49) | 15 | 90 % |
| Area 81 by mathpesto (on 31. January 2023, 19:44) | 85 | 96 % |
| The Big Renbans by Nai Night (on 18. February 2023, 22:00) | 18 | 94 % |
| Bite Marks by ViKingPrime (on 8. March 2023, 17:00) | 27 | 99 % |
| Unos - 8x8 Sudoku Pack by Joseph nehme (on 15. March 2023, 08:55) | 29 | 95 % |
| Unlucky Killers by bodemeister (on 9. May 2023, 03:02) | 19 | 94 % |
| The Big Bang by EricRathbun (on 12. June 2023, 14:23) | 31 | 94 % |
| Where's my sandwich? by Chilly (on 19. June 2023, 17:36) | 22 | 92 % |
