(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 | |
|---|---|---|---|
 | Parallel Shots (Arrow Killer Sudoku) by Cane_Puzzles (on 15. August 2021, 17:14) | 30 |  94 % |
| The Spandex Sandwich by PrimeWeasel (on 4. September 2021, 10:09) | 28 | 98 % |
| Square Dance by cristophermoore (on 16. February 2023, 19:24) | 67 | 94 % |
| Galactic Whispers by Knickolas (on 15. July 2023, 10:24) | 60 | 95 % |
| Zippery When Wet by marty_sears (on 20. November 2023, 03:01) | 175 | 99 % |
| Konferenz der Hellseher (Sudoku) by glum_hippo (on 22. March 2024, 05:05) | 26 | 92 % |
| SMOG - Buchstabenrätsel / Letter Puzzle by DocLogic (on 4. May 2024, 13:16) | 28 | 95 % |
| Ren-Bahn #1 [Renban U-Bahn] by Christounet (on 1. September 2025, 21:12) | 30 | 98 % |
| Suguru Chaos Deconstruction #2: Kropki Edition by mathpesto (on 16. February 2022, 03:51) | 158 | 99 % |
| [Fog of War Series] 22.Caged Snakey by AstralSky (on 13. March 2024, 14:02) | 131 | 96 % |
| Ice Cave by Agent (on 21. November 2023, 09:00) | 43 | 99 % |
| Arrow - Canal View by abed hawila (on 7. January 2022, 13:06) | 54 | 98 % |
| Unplugged by Xenonetix (on 7. August 2022, 02:02) | 56 | 95 % |
| Palenban (Renban+palindrome sudoku) by Qodec (on 11. September 2023, 20:28) | 72 | 93 % |
| SudokuCon Quilt by jwsinclair (on 15. April 2025, 21:40) | 70 | 95 % |
| Ripped Out by Black_Doom (on 28. July 2025, 16:18) | 78 | 97 % |
| Fault Lines by SeveNateNine (on 20. February 2025, 07:54) | 99 | 96 % |
| Bernis Geburtstag - Japanische Summen auf Klein'scher Flasche by ibag (on 15. June 2013, 15:25) | 37 | 93 % |
| NATUR - Buchstabenrätsel by DocLogic (on 2. January 2020, 16:41) | 44 | 93 % |
| Snakes Sandwiches & Chaos by emmettcito (on 8. August 2020, 04:39) | 16 | 98 % |
