(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 | |
|---|---|---|---|
 | Several Little Boxes by jsmirob (on 17. November 2022, 04:39) | 36 |  94 % |
| SC25 - Projected Sums by kuraban (on 25. November 2022, 09:32) | 21 | 95 % |
| Mods, Quads & Odds by ThePedallingPianist (on 15. October 2023, 22:19) | 93 | 98 % |
| ☾ 10-Suȵ Loop ☼ by ElChiglia (on 28. October 2023, 08:05) | 42 | 95 % |
| Heat Stroke by juggler (on 17. January 2024, 01:32) | 81 | 94 % |
| Pseudo Differences by marty_sears (on 20. February 2024, 21:00) | 96 | 98 % |
| You want sum? by Maximus (on 19. May 2024, 15:33) | 31 | 96 % |
| Thermal Arrows and Entropic Cages by MSDOS (on 30. May 2024, 07:23) | 65 | 95 % |
| Factor Map by ul-Rhymm (on 30. June 2024, 14:57) | 45 | 99 % |
| Yin-Yang Whisperominos by Die Hard (on 4. August 2024, 11:15) | 36 | 94 % |
| Shield Birds by 99%Sneaky (on 16. September 2024, 23:44) | 105 | 94 % |
| Slide & Seek #1: An X-wing on Diamonds by Pixel_StrengthReal (on 11. January 2025, 19:42) | 18 | 94 % |
| Dutch Flat Mates (Product Ltd + Skyscrapers) by Crusader175 (on 19. March 2025, 11:30) | 42 | 96 % |
| Chaconopia 101 by Mad-Tyas (on 2. September 2025, 15:49) | 30 | 100 % |
| Shmiddty business by NicoD (on 11. October 2025, 05:30) | 35 | 95 % |
| Japanische Summen - Krypto by ibag (on 22. July 2012, 09:20) | 83 | 99 % |
| Anti-Renban Killer by Phistomefel (on 10. March 2020, 13:05) | 94 | 97 % |
| Sudoku Variants Series (377) - Little Palindromes Sudoku by Richard (on 27. July 2022, 02:00) | 76 | 97 % |
| Hidden Thermo Sudoku by Prutsbeest (on 28. September 2021, 17:06) | 64 | 97 % |
| Heated Entropic Loop by yttrio (on 23. February 2024, 20:12) | 63 | 97 % |
