(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 | |
|---|---|---|---|
 | Tetropolis by sfushidahardy (on 4. October 2024, 17:18) | 19 |  99 % |
| Chaos Skyscrapers by JoWovrin (on 17. December 2021, 03:37) | 20 | 97 % |
| Archer's Entropy 3: Peace by Mad-Tyas (on 14. September 2022, 17:22) | 21 | 92 % |
| Japanese Sums #1: Killer Cages by lerroyy (on 15. February 2023, 19:52) | 20 | 96 % |
| Chaos Deconstruction: Japanese Sum by Phistomefel (on 13. February 2023, 20:00) | 101 | 98 % |
| Rainy Night by FryTheGuy (on 6. December 2021, 17:17) | 23 | 98 % |
| Riverbank - Episode 4: Nessie by henrypijames (on 20. May 2022, 09:26) | 18 | 98 % |
| Skyscraper Sums Deconstruction by Tacosian (on 24. January 2024, 04:07) | 18 | 100 % |
| Chaos Construction : Wrogn by lerroyy (on 8. June 2022, 20:59) | 61 | 98 % |
| Dynamic Construction by Niverio (on 6. April 2022, 00:26) | 37 | 99 % |
| Palindrome Arrow Sudoku by EliasKar (on 11. September 2021, 03:08) | 18 | 95 % |
| Sailing by ThePedallingPianist (on 15. February 2023, 00:18) | 22 | 98 % |
| Missile Command by Xenonetix (on 13. July 2022, 00:44) | 32 | 96 % |
| Even Small Prime by FryTheGuy (on 13. December 2021, 16:28) | 16 | 98 % |
| The inconvenient square root (chaos construction) by filuta (on 19. December 2021, 13:30) | 34 | 99 % |
| Crux by Jay Dyer (on 22. October 2023, 16:09) | 86 | 97 % |
| The S-Cell Miracle by Niverio (on 22. May 2022, 16:40) | 52 | 97 % |
| Chaos Construction: Increasing Path by KNT (on 3. October 2022, 23:31) | 98 | 97 % |
| Runway (Killer sudoku with maximum totals + arrows) by Qodec (on 6. October 2024, 19:06) | 53 | 95 % |
| Unique Japanese Sum Sudoku by tesseralis (on 28. July 2023, 05:34) | 73 | 98 % |
