(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 | |
|---|---|---|---|
 | Cold Sauerkraut (Nabner Thermo Sudoku) by Silverstep (on 24. August 2023, 17:47) | 30 |  91 % |
| Everything is Wrogn by Sumanta(ANU) (on 30. August 2023, 06:23) | 34 | 93 % |
| SET 103: palindromes and arrows by NicoD (on 17. August 2025, 05:30) | 67 | 96 % |
| Entropy miracle 11 by fractalminding (on 21. April 2026, 18:50) | 35 | 91 % |
| Aim High! (YY) by SennyK (on 17. January 2026, 18:01) | 107 | 96 % |
| Thermometer-Hochhäuser, 8x8 by pirx (on 12. December 2013, 18:08) | 64 | 94 % |
| Iso by ICHTUES (on 19. December 2021, 06:00) | 70 | 95 % |
| Adventskalender 2020, Türchen 7 - Twilight-Tapa by Zzzyxas (on 7. December 2020, 07:00) | 80 | 98 % |
| Would you like that toasted? by vitaminz (on 10. July 2024, 03:21) | 39 | 93 % |
| RAT RUN 8: Discontinuous by marty_sears (on 24. July 2024, 01:00) | 965 | 96 % |
| Anti-sudoku puzzle #3 by Nylimb (on 17. February 2020, 06:56) | 37 | 94 % |
| Think Outside the Cage by cristophermoore (on 22. September 2021, 03:35) | 42 | 98 % |
| Sealed Fate by Xendari (on 15. August 2022, 05:55) | 38 | 96 % |
| Twice a night by Fool on Hill (on 10. May 2023, 08:30) | 44 | 92 % |
| Fair and Square (Equality Cage + Arrow) by Schwupel (on 14. November 2023, 21:58) | 40 | 92 % |
| They check in, but they don't check out by Strosahl (on 3. October 2024, 06:13) | 48 | 94 % |
| Sudoku Variants Series (465) - Productive Killers by Richard (on 1. May 2026, 06:00) | 41 | 93 % |
| Mounted Archers by NurglesGift (on 24. October 2025, 20:15) | 54 | 92 % |
| Once a Copycat, Always a Copycat by marty_sears (on 9. May 2026, 11:52) | 96 | 97 % |
| Pseudo Cluedo by marty_sears (on 6. April 2024, 01:13) | 113 | 98 % |
