(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 | |
|---|---|---|---|
 | Solaris by Kafkapharnaum (on 3. March 2023, 15:34) | 17 |  96 % |
| Theseus (Chaos Construction Sudoku) by Mr.Menace (on 17. March 2023, 10:27) | 44 | 94 % |
| Modular Gap Sums – Reverse Skyscrapers – Chaos by Elliptical (on 3. April 2023, 23:48) | 13 | 100 % |
| 9x9 Chaos Construction: Minesweeper by SudokuExplorer (on 11. April 2023, 00:03) | 47 | 91 % |
| Castle in the Sky by filuta (on 23. April 2023, 12:35) | 13 | 100 % |
| U-Bahn with Quadrants for wooferzfg by KNT (on 22. April 2023, 16:45) | 32 | 99 % |
| Blackreach (U-Bahn Roller Coaster Cipher) by Agent (on 19. May 2023, 09:00) | 34 | 100 % |
| Crypto Japanese Halligen for Gliperal by KNT (on 4. June 2023, 06:51) | 22 | 97 % |
| Bletchley Park by fjam (on 11. June 2023, 20:40) | 18 | 100 % |
| U-Bahn with Empty Clues (4) by KNT (on 28. July 2023, 15:50) | 32 | 99 % |
| Roller Coaster mit Myxo by KNT (on 18. September 2023, 23:43) | 18 | 97 % |
| Missing Nine by FryTheGuy (on 4. September 2023, 01:40) | 12 | 95 % |
| What by zzw (on 21. September 2023, 04:17) | 54 | 91 % |
| Japanese Sums #3: Combination by lerroyy (on 3. November 2023, 12:57) | 13 | 98 % |
| Entropia: Heat Up by Mad-Tyas (on 27. November 2023, 10:55) | 47 | 97 % |
| Deconstruct Your Sandwiches by Tacosian (on 3. December 2023, 00:24) | 14 | 94 % |
| 99% Sneaky Whisper Lines by LittleNightmaresLady (on 6. December 2023, 18:38) | 13 | 98 % |
| Rock, Paper, Scissors by IcyFruit (on 4. January 2024, 16:33) | 23 | 95 % |
| Walls of Eternal Damnation (Secret Satan) by Agent (on 22. January 2024, 09:00) | 22 | 99 % |
| Secret Kingdoms by SenatorGronk (on 27. March 2024, 17:36) | 24 | 97 % |
