(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 | |
|---|---|---|---|
 | Cageless (X) Killer Sudoku by Shinya (on 13. March 2020, 17:26) | 60 |  99 % |
| The Puzzle Has Been SET by EricRathbun (on 2. July 2025, 00:00) | 61 | 97 % |
| Primal Instinct (Killer Sudoku) by Agent (on 25. July 2023, 09:00) | 165 | 97 % |
| Holographic Principle (Chaos Construction) by sfushidahardy (on 18. July 2024, 04:07) | 216 | 98 % |
| Quadrilateral by jwsinclair (on 20. April 2024, 18:03) | 104 | 98 % |
| 1000 Rooms by Qodec (on 10. May 2022, 22:37) | 44 | 94 % |
| Numbered Corridors by RockyRoer (on 7. July 2022, 13:25) | 48 | 97 % |
| Excluded by Niverio (on 19. March 2025, 18:30) | 129 | 97 % |
| Lemures by PulverizingPancake (on 2. September 2021, 20:40) | 79 | 96 % |
| Whisper of the killer snake by Joseph nehme (on 27. August 2021, 18:07) | 34 | 95 % |
| POKAL Buchstabenrätsel / Letter Puzzle by DocLogic (on 2. December 2022, 16:30) | 31 | 96 % |
| Hashiwokakero by Myxo (on 19. September 2023, 08:25) | 31 | 96 % |
| Krypto-U-Bahn - knapp daneben by ibag (on 22. May 2013, 22:33) | 47 | 96 % |
| Geburtstags-Mix Sudoku by Realshaggy (on 24. August 2020, 16:26) | 50 | 96 % |
| Build Your Own Killer: Master Designer 2 by Playmaker6174 (on 18. September 2023, 00:00) | 48 | 95 % |
| Synergy by Joseph nehme (on 7. August 2021, 08:11) | 77 | 95 % |
| Cheryl's Sudoku by Elytron (on 3. June 2025, 03:50) | 170 | 96 % |
| Wichtelkalender 2014 - April by April (on 1. April 2014, 00:00) | 37 | 98 % |
| Anti King XL Thermo Killer by MavericksJD (on 24. October 2020, 20:05) | 28 | 96 % |
| Encaged 9 by Joseph nehme (on 3. January 2021, 12:20) | 66 | 99 % |
