(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 | |
|---|---|---|---|
 | RedivideR by goodcity (on 17. March 2024, 16:36) | 20 |  93 % |
| Toutatis by IcyFruit (on 9. May 2024, 14:35) | 44 | 93 % |
| Induction (Nonconsecutive German Whispers Sudoku) by Phistomefel (on 14. June 2022, 09:05) | 140 | 96 % |
| Summation U-Bahn by Agent (on 19. September 2023, 09:00) | 69 | 97 % |
| Yin Equals Yang by SSG (on 9. September 2022, 07:16) | 57 | 96 % |
| Equilibrium 2: The Rune by Mad-Tyas (on 13. December 2022, 09:42) | 35 | 94 % |
| Headmaster's Toe (Anti-Knight, Renban) by juddimal (on 4. January 2025, 22:23) | 46 | 92 % |
| Negators by mathpesto (on 20. August 2022, 00:41) | 57 | 96 % |
| The Lonely White Dot by XeonRisq (on 14. December 2022, 21:00) | 54 | 95 % |
| Just Wrogn Enough by lerroyy (on 20. May 2022, 18:23) | 68 | 96 % |
| Thorny Tie (Killer Deconstruction) by Agent (on 12. July 2022, 09:00) | 60 | 100 % |
| Cryptic Coin (Arrow Kropki Sudoku) (ft. Tyrgannus) by Agent (on 9. September 2022, 09:00) | 70 | 98 % |
| Patches and Stitches by Sktx (on 15. November 2021, 13:00) | 31 | 97 % |
| The Corners are Even Double - Double Arrow Even/Odd Sudoku by Mr.Menace (on 29. August 2022, 20:08) | 30 | 93 % |
| The final test (Deconstruction/Killer/Anti-Knight/Connect the dots) by dumediat (on 30. December 2022, 03:17) | 26 | 99 % |
| Quicksort by filuta (on 29. June 2023, 14:15) | 12 | 92 % |
| Wichtels (später) Rätselsommer 2024 (11): Wichtel-Zwietracht by wichtel (on 11. October 2024, 20:23) | 15 | 100 % |
| Changeling Confusion by Scojo (on 31. October 2025, 23:31) | 15 | 94 % |
| Chaos Construction: Position Sums (9x9) by Jesper (on 12. October 2021, 20:35) | 79 | 100 % |
| Vignettes by zetamath (on 18. July 2022, 00:54) | 84 | 99 % |
