(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 | |
|---|---|---|---|
 | Godoku by sfushidahardy (on 25. May 2024, 20:28) | 15 |  94 % |
| Duet (Overlapping Tetrominous Loop) by the_cogito (on 28. June 2024, 22:34) | 13 | 100 % |
| Slitherbahn by KNT (on 5. August 2024, 09:00) | 31 | 100 % |
| What Do Killers Eat? by RockyRoer (on 24. September 2022, 14:44) | 61 | 100 % |
| Blackjack by Blashyrkh (on 14. May 2023, 12:28) | 71 | 95 % |
| Wichtelkalender 2012 (6) by wichtel (on 17. October 2012, 20:12) | 42 | 99 % |
| 9x9 Chaos Constructions: X-Sums and Arrows by abed hawila (on 19. June 2021, 19:51) | 47 | 98 % |
| Polar Vortex by mathpesto (on 2. October 2022, 22:42) | 44 | 91 % |
| Double Fireworks by antiknight (on 9. January 2023, 07:23) | 49 | 94 % |
| Slalom mit Torstangen, Teil 4 by pirx (on 2. October 2012, 21:44) | 33 | 97 % |
| Medieval Upheaval by Nordy (on 2. July 2022, 08:00) | 71 | 98 % |
| Collatz's Modifiers by mathpesto (on 12. September 2022, 03:53) | 30 | 96 % |
| Traces by arbitrary (on 27. April 2024, 22:27) | 74 | 97 % |
| Anti-Knight Killer Sudoku by trivial171 (on 4. May 2020, 00:46) | 54 | 95 % |
| 真笑Puzzles034--69Sandwiches (7)--XY Index2 by cdwg2000 (on 14. March 2021, 09:51) | 16 | 100 % |
| Mama Python 2 (Thermo Snake Sudoku) by peterchayward (on 10. April 2021, 04:31) | 21 | 98 % |
| Hidden Identity Killers by Fluster (on 3. May 2021, 19:35) | 38 | 97 % |
| Theorist's Key Change by Tyrgannus (on 14. November 2021, 21:04) | 17 | 91 % |
| X-sums Parity Confetti by Playmaker6174 (on 24. January 2022, 08:32) | 31 | 99 % |
| Chaos Construction: Equality by SSG (on 27. February 2022, 07:08) | 16 | 97 % |
