(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 | |
|---|---|---|---|
 | In Between the Spaces by XeonRisq (on 12. October 2022, 04:00) | 41 |  93 % |
| Chaotic Pointers by arbitrary (on 7. December 2024, 23:49) | 38 | 93 % |
| Chromosomes by ThePedallingPianist (on 3. January 2023, 01:15) | 114 | 96 % |
| Zwei Bärenfreunde by berni (on 11. August 2010, 14:16) | 21 | 92 % |
| Die Kryptos - S04E05: U-Bahn unter Hochhäusern by tuace (on 21. January 2020, 08:06) | 49 | 100 % |
| Avada Kedavra - A Magic Square Killer by Philipp Huber (on 8. July 2020, 22:38) | 73 | 93 % |
| Divisibility Squares Sudoku by ProwlingTiger (on 16. July 2020, 03:33) | 21 | 97 % |
| Hangover by Realshaggy (on 13. February 2022, 17:03) | 42 | 97 % |
| Valiant Viper in the King's Garden (Chess Snake Sudoku) by Nordy (on 5. April 2022, 01:20) | 31 | 95 % |
| Cavernous Construction by GarlicBredFries (on 5. May 2022, 06:47) | 79 | 98 % |
| Chaos Construction: diagonals by Prutsbeest (on 23. May 2022, 07:00) | 33 | 97 % |
| Entropy Focus by Mad-Tyas (on 8. September 2022, 14:54) | 47 | 96 % |
| Full Quads by mormagli (on 7. October 2022, 16:52) | 24 | 97 % |
| Headcrab by Blashyrkh (on 25. February 2023, 23:17) | 21 | 96 % |
| Escape Velocity (Arrow/XV) by damo_89 (on 3. June 2025, 22:53) | 64 | 95 % |
| Turbulence (Coordinate Arrows) by Sotehr (on 3. July 2025, 14:00) | 29 | 94 % |
| Neighbors Sudoku by Gliperal (on 26. June 2022, 14:51) | 81 | 97 % |
| Different, But Still Wrogn by DiMono (on 3. June 2022, 23:39) | 81 | 97 % |
| Ginnels & Snickets (Between Skyscraper) by tallcat (on 29. September 2022, 19:22) | 57 | 98 % |
| Drainers and Sires by mathpesto (on 23. June 2025, 15:52) | 52 | 96 % |
