(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 | |
|---|---|---|---|
 | Sum Kind of Maze by mormagli (on 28. July 2022, 19:24) | 18 |  92 % |
| Japanese Sums Nurikabe Arrows (9x9) by Xendari (on 1. January 2023, 08:55) | 16 | 95 % |
| Hybrid Star Battle Series (017) - Easy as ABC by BenceJoful (on 6. May 2023, 01:45) | 18 | 97 % |
| Is 4 a Low Digit? by blackjackfitz (on 30. August 2023, 03:23) | 24 | 92 % |
| Deconstruction of Whisper Tree (11x11) by SparkNights (on 4. February 2024, 07:05) | 40 | 97 % |
| Dust Torus (Black Hole) by heliopolix (on 14. September 2024, 00:00) | 22 | 98 % |
| Canyonlands (A38 + Rassi Silai) by sfushidahardy (on 16. March 2025, 17:07) | 17 | 93 % |
| Directed Entropy by egubachu (on 11. June 2025, 22:11) | 20 | 91 % |
| HeX-Sums by qoala (on 13. June 2025, 09:00) | 19 | 90 % |
| Minimality by Andrewsarchus (on 18. December 2025, 05:30) | 23 | 98 % |
| Liar X-Sums Cipher (ft. rdrd) by Christounet (on 18. January 2026, 23:58) | 17 | 100 % |
| Chaos Construction: Numbered Regions #1 by Jesper (on 24. September 2022, 15:15) | 170 | 100 % |
| Loop Aquarium by wooferzfg (on 23. October 2022, 20:25) | 46 | 96 % |
| Bushido (Star Battle Japanese Sums Fillomino) by Agent (on 6. December 2022, 09:00) | 49 | 99 % |
| Position Sums mit Renban-Streifen by glum_hippo (on 29. June 2021, 07:23) | 32 | 99 % |
| Jet Lag (Renban Killer Sudoku) by Agent (on 29. April 2022, 09:00) | 31 | 96 % |
| violently nostalgic by aqjhs (on 7. July 2025, 07:07) | 69 | 99 % |
| Counting Dimensions by Fenners (on 5. July 2025, 07:08) | 39 | 92 % |
| Ediacarium (Still Life Sudoku) by Qodec (on 12. October 2025, 18:37) | 35 | 95 % |
| Partial Manhattan Sudoku by Madmahogany (on 29. April 2020, 14:20) | 46 | 94 % |
