(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 | |
|---|---|---|---|
 | Anti3sis (Yin Yang Doubler Sudoku) by Agent (on 8. November 2022, 09:00) | 81 |  98 % |
| Baby Dragon by zetamath (on 18. November 2022, 17:23) | 136 | 95 % |
| Doublophobia by lepton (on 7. January 2023, 08:38) | 19 | 97 % |
| BAD Values Snooker by Zombie Hunter (on 21. February 2023, 20:24) | 17 | 95 % |
| No Wishing for More Wishes by ViKingPrime (on 10. September 2023, 02:00) | 11 | 98 % |
| Fair and Square (Equality Cage + Arrow) by Schwupel (on 14. November 2023, 21:58) | 35 | 93 % |
| Ring of Fire by lmdemasi (on 18. December 2023, 15:55) | 49 | 93 % |
| Tannenbaumino by cristophermoore (on 19. December 2023, 02:10) | 53 | 92 % |
| Run, run, run, run, run, run, run away by heliopolix (on 1. February 2024, 00:00) | 17 | 93 % |
| Prime Viking by heliopolix (on 21. February 2024, 13:55) | 12 | 95 % |
| Clockwork Yajilin: Parity Point by wisty (on 28. February 2024, 01:00) | 21 | 96 % |
| ☯ Yin-Yang-Loop ☯ by ElChiglia (on 1. April 2024, 00:17) | 26 | 93 % |
| Another “One of These Things” by Jrosas (on 4. April 2024, 16:47) | 20 | 91 % |
| Dual U-Bahn by Paletron (on 12. April 2024, 20:45) | 21 | 100 % |
| Mysterious Puzzle Survey by Niverio (on 8. July 2024, 01:00) | 10 | 95 % |
| Camouflage (Loop Sum Sudoku) by Agent (on 9. July 2024, 09:00) | 19 | 100 % |
| Double-wrapped X-sums by sanabas (on 19. July 2024, 04:58) | 12 | 90 % |
| Slitherlink Region Sum Hexuro by Nell Gwyn (on 22. July 2024, 07:10) | 11 | 98 % |
| Oil, Water and Soap by ViKingPrime (on 30. July 2024, 00:00) | 17 | 93 % |
| Porcelain by egubachu (on 5. August 2024, 10:32) | 62 | 94 % |
