(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 | |
|---|---|---|---|
 | KIIIocator: Ultimate Kill by starwarigami (on 11. November 2021, 03:16) | 18 |  91 % |
| Uneven Terrain (Parity Cave Sudoku) by Nordy (on 29. January 2022, 20:15) | 22 | 94 % |
| Lügende Rundwege / Slitherlink Liars by Phistomefel (on 21. March 2022, 12:15) | 32 | 99 % |
| A Game of Battleship! by Niverio (on 14. August 2022, 23:04) | 45 | 100 % |
| Chaos FilloSudokumino: Deconstruction by MagnusJosefsson (on 19. January 2023, 16:12) | 76 | 98 % |
| Pumpkin Wizard by Lizzy01 (on 15. October 2023, 14:09) | 17 | 93 % |
| Productivity Killer (BYOK+) by SeveNateNine (on 18. October 2023, 02:45) | 60 | 95 % |
| The Ankheg (Zippular Lines #4) by heliopolix (on 30. December 2023, 16:36) | 18 | 95 % |
| Tetris Sum Line by Chad (on 2. March 2024, 00:51) | 29 | 98 % |
| Landvermessung U-Bahn by KNT (on 27. June 2024, 01:47) | 19 | 100 % |
| Blemish [Even Squares, Kropki, Renban] by 3good5you (on 22. December 2024, 17:47) | 20 | 93 % |
| Trail of Prometheus (Secret Satan) by Agent (on 14. January 2025, 09:00) | 22 | 95 % |
| N-Lines by Qodec (on 6. August 2025, 16:53) | 25 | 93 % |
| TH13TEEN by IcyFruit (on 13. September 2025, 13:13) | 59 | 92 % |
| The Barrel (Arrow Sudoku) by tallcat (on 18. April 2021, 05:29) | 90 | 98 % |
| Sudokoban by DiMono (on 19. January 2023, 16:35) | 65 | 96 % |
| Rubber Bullets (10x10 Chaos Construction) by the_cogito (on 27. September 2022, 15:39) | 43 | 99 % |
| Chaos Loop by wooferzfg (on 1. December 2022, 05:49) | 41 | 99 % |
| Chaos Sums by wooferzfg (on 28. December 2022, 15:49) | 43 | 98 % |
| Hochhäuser mit Kellern, Teil 3 by pirx (on 3. July 2015, 18:00) | 34 | 99 % |
