(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 | |
|---|---|---|---|
 | All But One by Scruffamudda (on 16. August 2023, 15:20) | 83 |  94 % |
| X---V by NurglesGift (on 16. March 2025, 09:41) | 93 | 96 % |
| Double Chillomino by mathpesto (on 18. April 2024, 01:31) | 74 | 100 % |
| Tilt-a-Whirl by zetamath (on 17. October 2023, 17:38) | 75 | 93 % |
| Slitherlink Cave Sudoku by RockyRoer (on 16. August 2023, 14:05) | 67 | 97 % |
| The Keep by Myxo (on 31. January 2025, 15:00) | 73 | 93 % |
| Switchy by ICHTUES (on 11. December 2022, 06:00) | 69 | 95 % |
| That’s Even Better (Little Killer, Kropki Sudoku) by Mr.Menace (on 5. November 2024, 18:34) | 78 | 96 % |
| 123...9 by Qodec (on 28. February 2021, 14:48) | 65 | 95 % |
| Sudoku Variants Series (326) - Odd-Even Sandwich Sudoku by Richard (on 23. June 2021, 00:00) | 61 | 94 % |
| Battle With The Archers 24: Knight's Testimony by Playmaker6174 (on 10. December 2021, 10:29) | 62 | 93 % |
| Chaos Construction: Split Killers by XeonRisq (on 14. August 2022, 05:00) | 68 | 95 % |
| Entropy RSL by Mad-Tyas (on 2. May 2023, 09:02) | 65 | 97 % |
| A Hundred Cells of Chaos by Big Tiger (on 1. August 2023, 01:49) | 57 | 98 % |
| Halligen II by tuace (on 9. February 2014, 13:00) | 55 | 95 % |
| Reverb (Killer) by dumediat (on 9. October 2023, 23:11) | 60 | 97 % |
| Zodiac Project: Suguru's Surge by gdc (on 27. June 2024, 15:42) | 126 | 97 % |
| Sum-thing or Other by Jay Dyer (on 23. November 2024, 21:37) | 120 | 96 % |
| One total by psninn (on 28. November 2024, 17:35) | 58 | 95 % |
| Japanischer Summen-Rundweg 2358 (1) by Uhu (on 2. May 2017, 21:10) | 56 | 98 % |
