(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 | |
|---|---|---|---|
 | Infiltration by XeonRisq (on 19. February 2025, 22:00) | 24 |  93 % |
| Etude for a Broken Piano by juggler (on 3. May 2025, 19:44) | 43 | 96 % |
| Entropy miracle 10 by fractalminding (on 4. April 2026, 09:50) | 28 | 91 % |
| King's Gambit by GemmaOane (on 2. August 2023, 19:12) | 90 | 95 % |
| No Pun In Ten Did (Anti-Knight, Region Sum Line) by juddimal (on 18. July 2025, 06:40) | 89 | 96 % |
 | Pernicious by NicoD (on 18. May 2026, 17:58) | 61 | 97 % |
| KICK 4 by timyoth (on 8. April 2024, 11:05) | 109 | 93 % |
| KOPF - Buchstabenrätsel / Letter Puzzle by DocLogic (on 13. September 2020, 12:55) | 36 | 96 % |
| Positive Ring by SudokuExplorer (on 19. January 2021, 02:00) | 79 | 96 % |
| Lots of Fun by heliopolix (on 29. May 2024, 20:49) | 34 | 96 % |
| Different Neighbours U-Bahn by Paletron (on 2. June 2024, 11:30) | 38 | 96 % |
| Signposts by Blobz (on 20. May 2026, 16:00) | 53 | 94 % |
| Obstructed Skyline (fog) by jwsinclair (on 20. August 2023, 18:13) | 133 | 91 % |
| Mini-Höhle (2) by r45 (on 20. November 2018, 17:29) | 33 | 91 % |
| Toroidal Chess Sudoku #3 - Thermo by Rotstein (on 10. June 2020, 21:07) | 19 | 96 % |
| Z-Sums Sudoku 3 by Semax (on 4. October 2020, 08:21) | 17 | 98 % |
| Araf's Lunchbox (6x6) by udukos (on 17. June 2021, 21:54) | 13 | 98 % |
| Rounding Errors by Eclectic_Hoosier (on 12. May 2021, 16:52) | 18 | 96 % |
| Killers 123...go by abed hawila (on 21. May 2021, 09:02) | 60 | 95 % |
| Shuriken 手裏剣 by ___ (on 1. July 2021, 14:06) | 17 | 94 % |
