(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 | |
|---|---|---|---|
 | Chaos Construction: Pathfinder (9x9) by KNT (on 3. October 2022, 23:31) | 96 |  97 % |
| Crux by Jay Dyer (on 22. October 2023, 16:09) | 78 | 98 % |
| Chaos Deconstruction: Japanese Sum by Phistomefel (on 13. February 2023, 20:00) | 93 | 98 % |
| Whirlpool by FryTheGuy (on 26. August 2021, 17:16) | 19 | 95 % |
| Riverbank - Episode 4: Nessie by henrypijames (on 20. May 2022, 09:26) | 17 | 98 % |
| Chaos Construction : Wrogn by lerroyy (on 8. June 2022, 20:59) | 58 | 98 % |
| Japanese Japanese Sums Sums #1 by The Book Wyrm (on 30. November 2023, 22:11) | 20 | 98 % |
| Even Small Prime by FryTheGuy (on 13. December 2021, 16:28) | 16 | 98 % |
| Dynamic Construction by Niverio (on 6. April 2022, 00:26) | 34 | 99 % |
| Sailing by ThePedallingPianist (on 15. February 2023, 00:18) | 19 | 98 % |
| Missile Command by Xenonetix (on 13. July 2022, 00:44) | 30 | 95 % |
| Entropia (Skyscraper, Entropy) by Mad-Tyas (on 16. January 2023, 12:15) | 39 | 91 % |
| Palindrome Arrow Sudoku by EliasKar (on 11. September 2021, 03:08) | 15 | 94 % |
| The S-Cell Miracle by Niverio (on 22. May 2022, 16:40) | 50 | 97 % |
| Japanese Sums #2: Killer Cages Fillomino by lerroyy (on 3. March 2023, 14:29) | 15 | 98 % |
| Circled Killers by SparkNights (on 12. December 2023, 15:11) | 31 | 96 % |
| Working Nine To Five by fjam (on 8. January 2024, 20:03) | 16 | 94 % |
| Unique Japanese Sum Sudoku by tesseralis (on 28. July 2023, 05:34) | 70 | 98 % |
| Chaos In Frankfurt! (Secret Satan 2023) by Niverio (on 1. January 2024, 17:25) | 31 | 100 % |
| Hallig-Rundreise by tuace (on 13. April 2015, 00:47) | 41 | 100 % |
