(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 | |
|---|---|---|---|
 | O vs. X by ICHTUES (on 4. July 2021, 06:00) | 20 |  93 % |
| Five Stories by SSG (on 6. January 2022, 07:15) | 22 | 93 % |
| And Then There Were None by fjam (on 23. April 2022, 20:16) | 25 | 91 % |
| Colorguru Chaos Deconstruction: Palindromes by crispy16 (on 17. June 2022, 19:42) | 39 | 99 % |
| Lucky Arrows by PotatoHead21 (on 9. August 2022, 22:28) | 25 | 93 % |
| Beacons and Towers by Elliptical (on 18. September 2022, 21:21) | 20 | 97 % |
| Chaos Construction: Nonogram by Xendari (on 8. March 2024, 08:48) | 21 | 96 % |
| 4-color killer sudoku #2 by Nylimb (on 3. April 2021, 04:45) | 43 | 100 % |
| E ∩ tropy (Killer, Entropy Theme) by Crusader175 (on 20. May 2023, 16:00) | 27 | 93 % |
| Downtown Fog by apiyo (on 21. June 2023, 13:52) | 62 | 90 % |
| Heated Entropy by Mad-Tyas (on 14. December 2021, 00:10) | 63 | 97 % |
| Denver by ICHTUES (on 17. July 2022, 06:00) | 114 | 96 % |
| Emergence by Jay Dyer (on 27. May 2024, 00:01) | 84 | 96 % |
| Count me out ! [Deconstruction] by Christounet (on 14. April 2023, 01:18) | 45 | 99 % |
| Don't Know What We Dig 'em For by twototenth (on 9. November 2021, 08:00) | 44 | 100 % |
| Lügner Rundwege - Liar Loops by Calavera (on 17. November 2009, 19:32) | 62 | 97 % |
| Japanische Summen mit 50 by ibag (on 7. September 2018, 08:50) | 59 | 98 % |
| Cyclic Thermo Sudoku by trivial171 (on 29. April 2020, 03:43) | 14 | 93 % |
| Tangled Arrows (Arrow sudoku) by Aspartagcus (on 23. October 2020, 23:32) | 15 | 95 % |
| Arrow Sudoku X - Third time's the charm by udukos (on 3. April 2021, 21:26) | 46 | 96 % |
