(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 | |
|---|---|---|---|
 | Cross Whispers by Fool on Hill (on 1. June 2023, 15:08) | 60 |  93 % |
| Mixed Doubles by marty_sears (on 28. August 2023, 18:38) | 65 | 96 % |
| RAT RUN 8: Discontinuous by marty_sears (on 24. July 2024, 01:00) | 701 | 97 % |
| This or That - Killer Sudoku by Mr.Menace (on 31. August 2024, 19:22) | 66 | 92 % |
| Toroidal Snake - etwas verkürzt by lupo (on 4. February 2018, 23:53) | 21 | 94 % |
| Roller Coaster U-Bahn by Zzzyxas (on 22. August 2019, 18:25) | 58 | 99 % |
| Three Arrows by Onion Suit (on 5. May 2021, 02:31) | 24 | 94 % |
| Wave Sudoku by Vebby (on 26. May 2021, 19:06) | 18 | 95 % |
| Diamonds by abed hawila (on 6. June 2021, 17:16) | 20 | 96 % |
| Forwards & Backwards by zetamath (on 12. July 2021, 23:43) | 46 | 93 % |
| Norinori Castle Wall by SudokuExplorer (on 11. March 2022, 17:30) | 20 | 94 % |
| Rounded Repulsion by Qril (on 9. June 2022, 02:04) | 21 | 96 % |
| Mineshweepa by mnasti2 (on 10. August 2022, 20:45) | 24 | 94 % |
| Second Region X-Sums Chaos by Elliptical (on 20. November 2022, 21:22) | 43 | 98 % |
| Double Jointed by 99%Sneaky (on 2. September 2023, 19:00) | 23 | 93 % |
| Parity Poopers by aleph-0 (on 29. February 2024, 12:59) | 20 | 98 % |
| el quinto sol by aqjhs (on 27. November 2024, 05:00) | 23 | 96 % |
| Turn to Stone by Andrewsarchus (on 29. October 2025, 06:14) | 18 | 97 % |
| Heat Exchange by EdTheAlchemist (on 9. November 2025, 11:08) | 70 | 97 % |
| Pentominous Sum Lines by Xendari (on 19. October 2023, 23:22) | 63 | 97 % |
