(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 | |
|---|---|---|---|
 | Lion-Fish (Killer Sudoku) by abed hawila (on 6. March 2021, 18:51) | 93 |  96 % |
| Loopy Whisper X-Sums by yttrio (on 8. June 2024, 04:31) | 91 | 98 % |
| Hidden Thermo Sudoku by Prutsbeest (on 28. September 2021, 17:06) | 66 | 97 % |
| That's Sum Slithering by andreasv (on 16. April 2022, 08:56) | 38 | 97 % |
| Trust Me, I'm Lying by Chefofdeath (on 23. June 2022, 02:39) | 35 | 93 % |
| Hedge Maze by dennischen (on 20. May 2024, 10:10) | 32 | 91 % |
| Adventskalender 2025, Türchen 14 - Adventskerzen by Zzzyxas (on 14. December 2025, 07:00) | 36 | 97 % |
| Japanische Krypto-Summen-Trilogie (3) by ibag (on 31. December 2013, 07:00) | 70 | 99 % |
| Anti-Renban Killer by Phistomefel (on 10. March 2020, 13:05) | 95 | 96 % |
| Killomino by josh_johnson (on 9. July 2022, 04:16) | 50 | 94 % |
| Four Corner Shots by noswald (on 25. May 2024, 18:28) | 47 | 95 % |
| Which Room Were We In? by ChinStrap (on 13. January 2026, 18:56) | 43 | 93 % |
| Sum Line Sudoku #1 by Phistomefel (on 1. October 2022, 10:02) | 161 | 97 % |
| Distorted Reflections by meggen033 (on 10. March 2024, 14:46) | 73 | 93 % |
| Tapa-Berührungsrundweg by usp (on 16. July 2014, 00:00) | 65 | 98 % |
| Normal Lunchbox by Undar_Beyond (on 14. May 2020, 11:26) | 66 | 95 % |
| Waben Summenkropki Invers und knapp daneben by Luigi (on 3. February 2010, 14:09) | 48 | 96 % |
| Bernis Geburtstags-Transporteur by uvo (on 13. June 2013, 21:15) | 27 | 99 % |
| Wichtel 2019 (3): Die U-Bahn unter dem Geschenkelager by wichtel (on 9. July 2020, 20:01) | 50 | 100 % |
| Between the Little Killers by Stavros96 (on 25. August 2020, 12:08) | 50 | 93 % |
