(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 | |
|---|---|---|---|
 | Correspondence by Jay Dyer (on 17. May 2022, 21:46) | 21 |  94 % |
| Terminal Velocity by Tyrgannus (on 6. June 2022, 17:31) | 42 | 96 % |
| Bittersweet Candies 2 - A Regular 6x6 Sudoku Pack by Playmaker6174 (on 3. July 2022, 20:07) | 21 | 94 % |
| Jaguar's Paw (irregular 6x6) by Samish (on 23. July 2022, 10:10) | 21 | 95 % |
| The Trident by antiknight (on 12. September 2022, 11:02) | 63 | 95 % |
| Polyamorous Cages by Ennead (on 11. December 2022, 11:24) | 41 | 95 % |
| Many happy returns (Land survey/Quadruples/Chaos Construction/Cipher) by dumediat (on 10. February 2023, 13:42) | 20 | 98 % |
| SC32 - Double Arrow by kuraban (on 4. June 2023, 14:24) | 18 | 95 % |
| What's in the Box? by lmdemasi (on 22. August 2024, 13:56) | 45 | 96 % |
| Celtic Cross by ul-Rhymm (on 12. November 2024, 14:00) | 21 | 90 % |
| Hexaoctoquadri by mathpesto (on 20. March 2025, 16:05) | 44 | 96 % |
| Cutthroat by NicoD (on 4. April 2025, 05:17) | 21 | 92 % |
| Constantinople (U-Bahn with Nesting Clues) by sfushidahardy (on 23. August 2025, 00:31) | 25 | 100 % |
| Checks and Balances by MSDOS (on 24. November 2025, 05:46) | 44 | 96 % |
| Summation Slitherbahn by cyddrdrd (on 10. January 2026, 00:00) | 19 | 100 % |
| Some Sightline Circles Somedoku by blackjackfitz (on 4. May 2026, 15:15) | 24 | 92 % |
| Konami Code by TotallyNormalCat (on 10. March 2021, 23:30) | 102 | 97 % |
| Anti-Knight Killer Sudoku #3 by Phistomefel (on 11. February 2021, 23:20) | 122 | 95 % |
| King Arthur by oxjphs (on 13. August 2023, 06:37) | 65 | 95 % |
| Blue Arrow by Kaktuslav (on 10. February 2025, 20:35) | 66 | 96 % |
