(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 | |
|---|---|---|---|
 | Eternal Life by Sktx (on 20. May 2021, 12:35) | 18 |  100 % |
| Sirius by jovi_al (on 19. February 2022, 03:07) | 38 | 98 % |
| Imaginary Cages by brandon_bot (on 1. May 2022, 21:14) | 24 | 97 % |
| 3D2Y by udukos (on 9. November 2024, 20:45) | 34 | 98 % |
| Caudal Autotomy by DadJokes (on 19. August 2022, 21:11) | 26 | 97 % |
| Safe Distances by Emphyrio (on 26. September 2022, 16:54) | 45 | 93 % |
| Headcrab by Blashyrkh (on 25. February 2023, 23:17) | 19 | 95 % |
| Decoder [Akari Japanese Sums Fillomino] by wisty (on 25. December 2024, 15:31) | 20 | 98 % |
| Sunflower by RockyRoer (on 22. September 2021, 19:20) | 54 | 96 % |
| Cave Express (Japanese Sums Cipher) by Agent (on 21. February 2023, 09:00) | 47 | 99 % |
| Rundweg Family Photo by pokerke (on 14. February 2011, 00:57) | 77 | 100 % |
| Thermo + Killer + Anti-Knight by stimim (on 30. July 2020, 17:38) | 91 | 99 % |
| Triple Decker by Mimaamakim (on 29. August 2021, 20:28) | 32 | 98 % |
| The "Sum of Sums" Puzzle (that no one asked for) by Jeet Sampat (on 24. January 2023, 17:35) | 31 | 99 % |
| Modular Fillomino by mathpesto (on 16. November 2024, 03:08) | 90 | 98 % |
| Dedicated to wisty by Myxo (on 21. January 2025, 14:25) | 27 | 95 % |
| The Usual Suspects by zetamath (on 22. October 2021, 02:39) | 74 | 97 % |
| Whisper Whisper by Jay Dyer (on 20. August 2022, 13:08) | 42 | 99 % |
| String Quartet by IcyFruit (on 5. November 2023, 01:26) | 72 | 96 % |
| Serial Killers by starwarigami (on 10. April 2023, 06:44) | 93 | 97 % |
