(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 | |
|---|---|---|---|
 | Traces by arbitrary (on 27. April 2024, 22:27) | 75 |  97 % |
| Clean Sweep [Parity Sweepers, Quads, Difference Dots collab with Mathgeek] by Malrog (on 7. November 2024, 17:06) | 15 | 91 % |
| Stationary Loop Deconstruction (1-7) by Playmaker6174 (on 18. February 2025, 08:00) | 17 | 100 % |
| German Whispers Delux by Justalilguy (on 20. February 2025, 15:55) | 18 | 96 % |
| Klappstuhl by ICHTUES (on 27. August 2023, 06:00) | 66 | 97 % |
| (9x9) Chaos Construction: X-sums Doubled Limit by Playmaker6174 (on 16. March 2023, 04:14) | 59 | 96 % |
| Shuriken by crispy16 (on 24. May 2022, 19:43) | 40 | 94 % |
| Donuts [Killer] by Malrog (on 8. October 2024, 00:55) | 40 | 93 % |
| Knapp daneben-Tapa by flooser (on 10. June 2009, 12:32) | 88 | 96 % |
| Akari Sudoku by Prasanna16391 (on 30. July 2020, 00:05) | 18 | 90 % |
| Rounded Killer Sudoku by RockyRoer (on 7. January 2021, 00:00) | 18 | 90 % |
| Ranked Top 9 Best Digits (Rank Sudoku) by purpl (on 22. March 2022, 21:59) | 18 | 97 % |
| Sæpenumerō by mathpesto (on 4. May 2022, 04:17) | 32 | 98 % |
| 4's and 7's by the_cogito (on 26. July 2022, 21:20) | 18 | 92 % |
| Quarrowdruples by Joseph nehme (on 19. August 2022, 17:32) | 23 | 90 % |
| Death Spiral by EricRathbun (on 4. February 2023, 18:12) | 24 | 93 % |
| Liar Sum Before Digit 9 #1 by Playmaker6174 (on 2. April 2023, 13:07) | 17 | 93 % |
| Nansuke Sudoku (formerly Word Search Sudoku) by ufdigga (on 13. April 2023, 23:21) | 18 | 97 % |
| Moriarty Leaves A Clue by HalfBakedLunatic (on 19. August 2023, 23:43) | 45 | 93 % |
| XOR #2 by Blashyrkh (on 8. September 2023, 14:06) | 35 | 96 % |
