(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 | |
|---|---|---|---|
 | Glyphs #4 by damasosos92 (on 28. January 2023, 20:42) | 27 |  92 % |
| King by ICHTUES (on 22. August 2021, 06:00) | 63 | 96 % |
| Krypto Sandwich Sudoku by Realshaggy (on 30. December 2019, 15:22) | 46 | 91 % |
| Hells Bells by Christounet (on 10. July 2023, 23:15) | 93 | 96 % |
| Taurus (Arrow Killer) by tallcat (on 4. May 2021, 13:32) | 51 | 97 % |
| nabneR by zetamath (on 4. July 2021, 17:35) | 71 | 98 % |
| Mind the Gap by juggler (on 6. July 2024, 06:05) | 70 | 97 % |
| Bizarro Killer by Strosahl (on 12. June 2020, 05:38) | 27 | 97 % |
| Rotated Lines Sudoku by brandon_bot (on 8. December 2020, 04:12) | 17 | 94 % |
| Triangular Cages Killer Sudoku (Dreieckszahl) by Jviscus (on 23. January 2021, 03:25) | 27 | 96 % |
| From Nothing, Something by Gliperal (on 8. May 2022, 09:32) | 15 | 92 % |
| Get Up on the Hydra's Back! (Chaos Construction) by tesseralis (on 20. August 2022, 10:38) | 48 | 100 % |
| Sigma Pi by IcyFruit (on 7. December 2023, 21:50) | 105 | 93 % |
| Loose associations (Numbered rooms/Remote sums/Region sum lines) by dumediat (on 6. October 2023, 21:39) | 57 | 93 % |
| Killer Sudoku - The Cloverleaf by Phistomefel (on 6. September 2020, 13:21) | 103 | 94 % |
| Japanese Sums Sudoku - with negatives by RockyRoer (on 4. September 2023, 14:33) | 31 | 97 % |
| Equality Cages by Big Tiger (on 29. May 2021, 00:24) | 22 | 98 % |
| X---V*8 by NurglesGift (on 17. August 2025, 16:10) | 54 | 93 % |
| Signature Sudoku by Nell Gwyn (on 5. September 2022, 06:10) | 19 | 98 % |
| Bluth's by mathpesto (on 21. May 2023, 03:08) | 48 | 96 % |
