(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 | |
|---|---|---|---|
 | Kropki XV Sudoku - Progressive Power-Up by DiMono (on 6. January 2022, 18:46) | 30 |  93 % |
| Ratio (-) Arrow Sudoku by Florian Wortmann (on 10. April 2022, 16:06) | 25 | 91 % |
| Double or Nothing by Oddlyeven (on 14. December 2022, 17:06) | 23 | 99 % |
| Peel Back the Layers by XeonRisq (on 10. December 2023, 04:00) | 25 | 92 % |
| Lime Lines II by Calesch (on 10. March 2024, 21:03) | 26 | 92 % |
| Stolen Numerals XV*3 by NurglesGift (on 6. July 2024, 22:12) | 79 | 96 % |
| Writing a Zeugma by 99%Sneaky (on 7. July 2024, 22:21) | 29 | 95 % |
| Treasury Island by Morisenseiisgod (on 16. May 2025, 18:09) | 55 | 93 % |
| Orchid by mathpesto (on 6. September 2025, 19:03) | 81 | 98 % |
| Taste the Tension by GameWorksRP (on 27. October 2025, 11:54) | 58 | 94 % |
| Rank Up 20.mg12.3 - Fill-rank-omino by MathGuy_12 (on 27. January 2026, 00:11) | 53 | 92 % |
| Under Pressure by Rab3aron (on 7. April 2026, 12:01) | 24 | 90 % |
| Unique Aquarium Sudoku by Sam Knott (on 22. September 2020, 15:17) | 56 | 98 % |
| Qarpet Beater by Qodec (on 14. November 2020, 14:59) | 62 | 93 % |
| Nineteen? (X-sums Chaos Construction 2) by Lizzy01 (on 13. April 2022, 21:17) | 55 | 99 % |
| Crossroads on Another World by JeffWajes (on 12. December 2025, 07:23) | 64 | 97 % |
| Säntis (collab with ICHTUES) by Florian Wortmann (on 25. October 2023, 20:05) | 128 | 96 % |
| Tapa-Höhle 1 by usp (on 13. March 2015, 00:00) | 58 | 92 % |
| Little Thermo Sudoku by Alexander Rappa (on 16. June 2020, 16:15) | 34 | 96 % |
| Negative Caving by Mark Sweep (on 11. December 2020, 10:00) | 28 | 96 % |
