(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 | |
|---|---|---|---|
 | Ghost Digit by jwsinclair (on 15. October 2021, 19:25) | 30 |  95 % |
| Kropki XV Sudoku - Progressive Power-Up by DiMono (on 6. January 2022, 18:46) | 30 | 93 % |
| Ratio (-) Arrow Sudoku by Florian Wortmann (on 10. April 2022, 16:06) | 25 | 91 % |
| Double or Nothing by Oddlyeven (on 14. December 2022, 17:06) | 23 | 99 % |
| Shady Combination #1: Cave, Pentominos, Slitherlink, Snake by Myxo (on 9. January 2023, 15:33) | 50 | 99 % |
| Peel Back the Layers by XeonRisq (on 10. December 2023, 04:00) | 25 | 92 % |
| Lime Lines II by Calesch (on 10. March 2024, 21:03) | 26 | 92 % |
| Writing a Zeugma by 99%Sneaky (on 7. July 2024, 22:21) | 29 | 95 % |
| X---V*Whisper by NurglesGift (on 11. October 2025, 14:38) | 59 | 95 % |
| Tenfinity by ThePedallingPianist (on 23. November 2025, 18:45) | 51 | 95 % |
| Qarpet Beater by Qodec (on 14. November 2020, 14:59) | 61 | 93 % |
| Shiny (Cave; Suguru/Fillomino) by MaizeGator (on 27. August 2024, 04:34) | 58 | 96 % |
| Cavalry Archer (Anti-Knight Arrow Sudoku) by Phistomefel (on 2. June 2021, 21:09) | 197 | 97 % |
| Tapa-Höhle 1 by usp (on 13. March 2015, 00:00) | 58 | 92 % |
| Little Thermo Sudoku by Alexander Rappa (on 16. June 2020, 16:15) | 34 | 96 % |
| Negative Caving by Mark Sweep (on 11. December 2020, 10:00) | 28 | 96 % |
| Murmuration (Little Killer) by emmettcito (on 31. March 2021, 19:38) | 33 | 97 % |
| XY-Cages by glum_hippo (on 1. May 2022, 06:05) | 62 | 93 % |
| Lucky (Symmetrical Palindromic Arrows) by AnalyticalNinja (on 26. July 2022, 23:55) | 33 | 97 % |
| Abstract Nonsense by Oddlyeven (on 13. August 2022, 23:34) | 72 | 97 % |
