(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 | |
|---|---|---|---|
 | The "Sum of Sums" Puzzle (that no one asked for) by Jeet Sampat (on 24. January 2023, 17:35) | 34 |  99 % |
| A Quiver of Snakes by The Book Wyrm (on 18. June 2023, 10:07) | 31 | 93 % |
| Schrödinger 303: S-Duality by ViKingPrime (on 9. September 2024, 17:30) | 32 | 91 % |
| Thermal Signatures by Kafkapharnaum (on 12. May 2025, 01:13) | 57 | 98 % |
| Foggy Banren by DarthParadox (on 9. August 2024, 23:18) | 89 | 94 % |
| Japanische Summen mit 50 by ibag (on 7. September 2018, 08:50) | 61 | 98 % |
| Bullseye Sudoku by RockyRoer (on 29. July 2020, 21:59) | 52 | 96 % |
| Eternal Life by Sktx (on 20. May 2021, 12:35) | 23 | 99 % |
| O vs. X by ICHTUES (on 4. July 2021, 06:00) | 23 | 92 % |
| Chaos Construction: Loop Sum by Phistomefel (on 8. April 2022, 18:16) | 141 | 99 % |
| Lucky Arrows by PotatoHead21 (on 9. August 2022, 22:28) | 28 | 92 % |
| Arrow Replica Addition by PotatoHead21 (on 30. April 2023, 17:34) | 24 | 90 % |
| Opposition (Black holes/Killer/Teleporting little killer) by dumediat (on 9. February 2024, 12:00) | 22 | 99 % |
| Meinsweeper by fjam (on 24. June 2024, 20:01) | 24 | 91 % |
| Chaotic Addition by Manta-Ray (on 7. October 2024, 13:09) | 20 | 93 % |
| Pseudocount by I Love Sleeping (on 9. November 2024, 15:30) | 21 | 92 % |
| A Song of Ice and Fire by SenatorGronk (on 17. February 2025, 22:29) | 24 | 93 % |
| a new way out by aqjhs (on 17. December 2025, 20:26) | 25 | 95 % |
| Oops! All Regions by ChinStrap (on 12. November 2025, 18:30) | 57 | 95 % |
| Read Between the Lines (Build Your Own Puzzle) by tallcat (on 8. December 2021, 03:56) | 96 | 100 % |
