(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 | |
|---|---|---|---|
 | Chaotically Coordinated Arrows by Piatato (on 3. March 2022, 19:58) | 64 |  98 % |
| Crypto Japanese Cave (2) by KNT (on 13. October 2022, 23:25) | 63 | 100 % |
| Diagonality by The Book Wyrm (on 15. September 2025, 23:59) | 65 | 92 % |
| Squares with Chaotic Circles by thoughtbyte (on 18. January 2024, 09:07) | 44 | 99 % |
| Kashmir by lerroyy (on 29. March 2022, 20:26) | 55 | 96 % |
| Chaos Construction: Liars (8x8) by Gliperal (on 22. April 2024, 20:38) | 23 | 93 % |
| Delirium (Chaos Construction) by heliopolix (on 25. October 2024, 18:14) | 52 | 99 % |
| Urban Madness (Chaos Construction) by Mad-Tyas (on 23. August 2025, 05:05) | 26 | 92 % |
| Taijitu (ft. KNT) by TotallyNormalCat (on 26. May 2022, 18:00) | 55 | 95 % |
| Loop Nurikabe by wooferzfg (on 2. February 2023, 16:31) | 115 | 98 % |
| Bubble Trouble by Stavros96 (on 16. March 2021, 12:01) | 32 | 98 % |
| The Great Overlap by filuta (on 2. February 2024, 16:27) | 27 | 98 % |
| U-Bahn mit gemischten Hinweisen (Teil 3) by Zzzyxas (on 28. December 2019, 13:32) | 40 | 99 % |
| Mods, Quads, Odds & Schröds by ThePedallingPianist (on 17. October 2023, 15:00) | 45 | 98 % |
| Carry the Three (two-digit arrow sudoku) by clover (on 30. October 2020, 18:10) | 30 | 97 % |
| Genome by Tyrgannus (on 7. July 2021, 21:33) | 44 | 97 % |
| Stingray (Killer Sudoku) by FryTheGuy (on 13. August 2021, 05:40) | 21 | 95 % |
| Build your own samurai sudoku by filuta (on 7. September 2021, 01:37) | 10 | 95 % |
| Sudoku Assembly Required by Saphie (on 1. March 2022, 19:57) | 20 | 100 % |
| Chaos Construction: Thermos by XeonRisq (on 8. May 2022, 01:00) | 19 | 98 % |
