(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 | |
|---|---|---|---|
 | Castle Wall Delta #1 (10x10) by Jesper (on 22. May 2021, 17:38) | 71 |  98 % |
| Killer Sudoku - The Cloverleaf by Phistomefel (on 6. September 2020, 13:21) | 88 | 94 % |
| Equality Cages by Big Tiger (on 29. May 2021, 00:24) | 18 | 97 % |
| Arrow Madness by antiknight (on 20. March 2022, 00:35) | 24 | 90 % |
| Killer Lunchboxes by Undar_Beyond (on 16. June 2020, 16:35) | 52 | 98 % |
| Bizarro Killer by Strosahl (on 12. June 2020, 05:38) | 26 | 98 % |
| Japanese Sums Sudoku - with negatives by RockyRoer (on 4. September 2023, 14:33) | 28 | 97 % |
| Sandwich Sudoku - Find x!!!! Part 4 by ProwlingTiger (on 31. May 2020, 00:45) | 19 | 96 % |
| Dust Storm by Gliperal (on 7. June 2022, 23:29) | 18 | 91 % |
| Fourberie by ViKingPrime (on 26. May 2023, 13:30) | 16 | 95 % |
| Dutch Dominoes by Black_Doom (on 29. May 2024, 07:55) | 15 | 96 % |
| Mind the Gap by juggler (on 6. July 2024, 06:05) | 52 | 96 % |
| Walking a Nine Line (Chaos Construction) by the_cogito (on 5. February 2023, 16:19) | 40 | 95 % |
| Draft Picks by ViKingPrime (on 11. September 2024, 16:30) | 20 | 99 % |
| Myriad of Triad by Tyrgannus (on 18. April 2021, 22:04) | 28 | 94 % |
| Urban Sprawl by jwsinclair (on 27. July 2022, 18:56) | 28 | 97 % |
| Bluth's by mathpesto (on 21. May 2023, 03:08) | 41 | 96 % |
| Doppelte Adventssummen 4. Advent by Luigi (on 20. December 2015, 08:04) | 52 | 96 % |
| Rotated Lines Sudoku by brandon_bot (on 8. December 2020, 04:12) | 15 | 93 % |
| Crowded Square by jwsinclair (on 3. March 2022, 19:31) | 12 | 93 % |
