(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 | |
|---|---|---|---|
 | 4'33" by ndsurgenor (on 28. September 2021, 15:35) | 36 |  97 % |
| Just Knights and Arrows by GBPack (on 18. November 2021, 21:53) | 24 | 90 % |
| Nonconsecutive Palindrome Sudoku #1 by GBPack (on 24. November 2021, 22:15) | 20 | 92 % |
| Fifteen All by Phurba (on 10. June 2024, 12:54) | 64 | 91 % |
| The Spectrum of Sunlight by egubachu (on 20. December 2024, 15:31) | 49 | 91 % |
| GCF by RockyRoer (on 14. February 2025, 14:39) | 17 | 97 % |
| Calembour by Jobo (on 28. May 2025, 09:01) | 38 | 94 % |
| Octogonapus by isajo4002 (on 29. June 2025, 15:17) | 36 | 90 % |
| Mushy Peas by Oddlyeven (on 14. November 2025, 23:02) | 19 | 92 % |
| Sea Skeleton [Classic Sudoku] by wisty (on 25. October 2022, 20:28) | 69 | 95 % |
| Polymorphic Rooms (collab with yttrio) by Bellsita (on 6. August 2023, 02:40) | 124 | 99 % |
| Intersections by IcyFruit (on 8. February 2024, 14:27) | 128 | 98 % |
| Streuung by Myxo (on 24. July 2024, 13:27) | 68 | 93 % |
| Dadly Sandwich by Cane_Puzzles (on 30. June 2022, 17:11) | 44 | 96 % |
| Stranded Friends by DarthParadox (on 14. July 2023, 00:12) | 45 | 92 % |
| Royal Isolation by Jacoba (on 8. September 2025, 17:24) | 51 | 91 % |
| Raw Spaghetti (equal sums lines sudoku) by Aspartagcus (on 23. June 2022, 23:19) | 73 | 97 % |
| A Beautiful Nightmare by Allagem (on 3. March 2024, 11:22) | 73 | 90 % |
| The Door around the Corner by XeonRisq (on 16. July 2023, 20:00) | 126 | 98 % |
| Noch ein 3D Rundweg by Calavera (on 31. December 2009, 05:49) | 63 | 98 % |
