(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 | |
|---|---|---|---|
 | Counterproductive by marty_sears (on 24. June 2025, 10:47) | 175 |  96 % |
| Anti-killer Sudoku by JoJoMcFroYo (on 26. June 2020, 14:55) | 25 | 90 % |
| X-Parity by LKegel (on 19. February 2021, 17:31) | 22 | 96 % |
| Lil' Kill by PrimeWeasel (on 11. March 2021, 07:29) | 38 | 90 % |
| Little Killer Thermo Palindrome Sudoku by Cane_Puzzles (on 19. March 2021, 16:16) | 48 | 94 % |
| Sandwich-Sudoku mit Average Arrows by glum_hippo (on 18. April 2021, 06:00) | 66 | 100 % |
| Hybridsudoku: Winterurlaub in Südtirol by glum_hippo (on 5. December 2021, 19:52) | 21 | 94 % |
| Ring Of Entropy by crispy16 (on 7. September 2022, 15:56) | 29 | 99 % |
| Bouquet of Poppies by Sotehr (on 17. January 2025, 10:00) | 47 | 90 % |
| Pentopia Rundweg by tuace (on 22. April 2019, 09:55) | 65 | 99 % |
| LM 2018 Countdown: Japanisches Summen-Masyu by Uhu (on 7. June 2018, 09:06) | 47 | 96 % |
| Six dots by Lutterot (on 18. May 2023, 22:46) | 40 | 92 % |
| Quiet Self-Reflection by Nordy (on 16. February 2025, 08:30) | 71 | 99 % |
| Doppelter Rundweg by SilBer (on 4. July 2009, 11:21) | 83 | 95 % |
| Valence by zetamath (on 12. August 2021, 19:08) | 60 | 96 % |
| Perfect Squares by ICHTUES (on 23. January 2022, 06:00) | 22 | 91 % |
| Which is Which, Again? by DJV (on 22. February 2023, 05:02) | 46 | 95 % |
| Beyond (Indexing Miracle) by Crusader175 (on 27. August 2023, 14:00) | 22 | 95 % |
| No Kings by Merdock (on 31. August 2025, 03:04) | 45 | 95 % |
| Loses Kalenderblatt April 2019 (1/2) by April (on 1. April 2019, 00:00) | 28 | 95 % |
