(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 | |
|---|---|---|---|
 | Anti-knight Thermo Sudoku #2 - Thermocouples by RSP (on 19. July 2020, 19:57) | 100 |  99 % |
| X-Sums & Sandwiches by kolot (on 2. April 2022, 03:02) | 93 | 99 % |
| Roller Coaster mit Extras 8 by Uhu (on 19. August 2018, 10:12) | 52 | 98 % |
| Cryptic Skyscrapers (Alphabet Soup) by emmettcito (on 21. March 2021, 00:30) | 31 | 98 % |
| Renber Whispan #2 by Sktx (on 8. August 2023, 11:49) | 31 | 96 % |
| Stostone Cold (Chaos Construction) by Phistomefel (on 10. April 2024, 20:09) | 88 | 98 % |
| Ambiguous Entropy by XeonRisq (on 28. December 2022, 23:00) | 149 | 97 % |
| Double Agent by DadJokes (on 29. September 2022, 21:48) | 21 | 97 % |
| JCQ #5: Fawlty Towers (Liar Thermo Killer Sudoku) by peterchayward (on 17. July 2020, 11:13) | 40 | 97 % |
| Fishie by zetamath (on 7. September 2021, 01:33) | 54 | 94 % |
| Japanese Sums Fillomino (10x10) by Jesper (on 2. December 2021, 09:41) | 51 | 99 % |
| Parity sections Sudoku by stephane.bura (on 25. May 2020, 08:35) | 15 | 92 % |
| Stitch the Broken Ring by LuckyNumber8 (on 13. April 2021, 01:43) | 17 | 92 % |
| arROw SudOkU rEduX by filuta (on 20. April 2021, 13:49) | 16 | 92 % |
| Drumsticks by antiknight (on 18. May 2022, 12:01) | 32 | 92 % |
| Hybrid Star Battle Series (017) - Easy as ABC by BenceJoful (on 6. May 2023, 01:45) | 16 | 96 % |
| Is 4 a Low Digit? by blackjackfitz (on 30. August 2023, 03:23) | 22 | 90 % |
| Inequalities by Ennead (on 31. October 2023, 11:53) | 15 | 98 % |
| Varianten-Samurai-Sudoku by JonaS2010 (on 9. September 2018, 09:09) | 56 | 98 % |
| Graffiti: A yajilomino experience (Fillomino/Yajilin) by dumediat (on 22. August 2023, 04:07) | 44 | 98 % |
