(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 | |
|---|---|---|---|
 | Bahamas by Qodec (on 24. April 2021, 20:43) | 112 |  97 % |
| Yin Doubles Yang (Killer + Yin Yang) by damo_89 (on 8. June 2024, 17:24) | 141 | 97 % |
| Anti-8 Killer by Blashyrkh (on 25. September 2023, 20:51) | 83 | 94 % |
| Classic Arrow Sudoku by Phistomefel (on 11. October 2020, 09:48) | 132 | 96 % |
| Sandwich Thermo Arrow Sudoku by Lizzy01 (on 9. May 2021, 20:17) | 24 | 90 % |
| Sudoku Variants Series (369) - Killer - Hidden Arrows Sudoku by Richard (on 4. May 2022, 01:00) | 69 | 97 % |
| Cursed Quiver 2 (Region Sum Arrows CC) by Xendari (on 16. December 2022, 08:13) | 45 | 98 % |
| HeatTen Up by djorr (on 20. February 2023, 14:00) | 25 | 92 % |
| Unique Killers by Yawnus (on 24. February 2023, 11:50) | 50 | 96 % |
| Odd Cages by Phantou (on 18. July 2023, 22:40) | 44 | 94 % |
| Writing a Zeugma by 99%Sneaky (on 7. July 2024, 22:21) | 23 | 94 % |
| Japanische Summen-Höhle 2358 by Uhu (on 1. August 2017, 22:32) | 48 | 98 % |
| Shrug by zetamath (on 15. December 2022, 16:33) | 111 | 97 % |
| Even Trios Killer Sudoku by Quarterthru (on 14. September 2020, 12:00) | 33 | 98 % |
| Short THERM 12+1 by Lisztes (on 13. November 2020, 01:00) | 32 | 90 % |
| FABRIK - Buchstabenrätsel / Letter puzzle by DocLogic (on 29. September 2021, 18:05) | 30 | 96 % |
| Known Unknowns (159 killer) by Chilly (on 27. October 2021, 11:12) | 33 | 97 % |
| 6x6 Hypercube by DiMono (on 18. February 2022, 23:40) | 27 | 95 % |
| Antiking Kaleidoscope (Stitched Rainbow VI) by thoughtbyte (on 7. August 2022, 03:16) | 35 | 96 % |
| Prime Party by Realshaggy (on 22. September 2022, 01:17) | 28 | 95 % |
