(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 | |
|---|---|---|---|
 | Sumsweeper by Xenonetix (on 9. May 2022, 01:33) | 52 |  96 % |
| Which Blare? by XeonRisq (on 28. August 2022, 22:00) | 17 | 93 % |
| Haisudoku Thermoline (Thermo Sudoku+Haisu hybrid) by AnalyticalNinja (on 15. November 2022, 03:02) | 33 | 100 % |
| Three-Line Riddle by JeremyDover (on 28. November 2022, 23:35) | 23 | 99 % |
| A Blind Killer by bodemeister (on 17. January 2023, 08:29) | 16 | 96 % |
| Broken Entropy by SeveNateNine (on 23. March 2023, 00:46) | 16 | 96 % |
| {Arrows,Collection} by Prof.Dori (on 13. June 2023, 14:26) | 49 | 96 % |
| Assassins by The Book Wyrm (on 8. November 2023, 00:14) | 25 | 96 % |
| Centroid by DarthParadox (on 24. May 2024, 17:57) | 26 | 91 % |
| Battleship Lighthouse Hashikabe by Nell Gwyn (on 2. June 2024, 05:10) | 16 | 96 % |
| Underground Traffic (U-Bahn tetromino) by Samish (on 10. October 2024, 12:09) | 23 | 99 % |
| Threads by arbitrary (on 29. November 2024, 18:47) | 21 | 95 % |
| Fearfully and Wonderfully Made by MathGuy_12 (on 19. April 2025, 00:52) | 21 | 95 % |
| who wants seconds? by aqjhs (on 9. May 2025, 02:00) | 20 | 96 % |
| Chaos Construction: X-Sums (9x9) by Jesper (on 21. June 2021, 08:34) | 117 | 96 % |
| Japanische Summen PQR by tuace (on 4. November 2016, 15:30) | 51 | 98 % |
| Fishie by zetamath (on 7. September 2021, 01:33) | 58 | 94 % |
| Battle With The Archers 41: The Fate of Three Worlds by Playmaker6174 (on 9. October 2023, 10:01) | 57 | 96 % |
| Border Square Diagonals by Phistomefel (on 21. May 2024, 19:16) | 108 | 97 % |
| Line of Sight Chaos Production (9x9) by RockyRoer (on 4. February 2022, 03:10) | 39 | 99 % |
