(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 | |
|---|---|---|---|
 | Supercell by tesseralis (on 14. June 2022, 23:37) | 24 |  90 % |
| Deep sea weirdity (Between lines sudoku) by Lizzy01 (on 15. June 2022, 22:38) | 26 | 97 % |
| Hidden Full Rank by RockyRoer (on 25. June 2022, 14:45) | 42 | 100 % |
| Some Octopus Somedoku by blackjackfitz (on 18. May 2024, 22:51) | 23 | 95 % |
| Stronghold by fjam (on 31. May 2024, 19:04) | 23 | 93 % |
| Assigned Pentominoes Loop #2 (18x18) by Playmaker6174 (on 21. March 2026, 06:00) | 25 | 99 % |
| Fourteen (Killer Sudoku) by FryTheGuy (on 8. August 2021, 08:13) | 80 | 98 % |
| Try-ominos by damasosos92 (on 26. September 2024, 20:37) | 51 | 98 % |
| Keep Talking [And No One Explodes] by zetamath (on 27. December 2021, 20:54) | 105 | 97 % |
| Fünf aßen Neun by MavericksJD (on 30. January 2022, 19:53) | 31 | 95 % |
| Where did the king go? by Jagga (on 20. August 2022, 16:04) | 30 | 91 % |
| Roman Hieroglyph by lepton (on 17. January 2023, 17:20) | 28 | 97 % |
| The Postman Problem by ThePedallingPianist (on 6. July 2023, 13:16) | 29 | 95 % |
| Same Old Same Old by MathGuy_12 (on 18. July 2025, 23:23) | 55 | 97 % |
| Your Own Medicine (Satan 2025) by MathGuy_12 (on 20. March 2026, 23:49) | 29 | 91 % |
| Doubler Chaos (Chaos Construction) by Mad-Tyas (on 19. November 2024, 23:39) | 137 | 96 % |
| The Barrel (Arrow Sudoku) by tallcat (on 18. April 2021, 05:29) | 94 | 98 % |
| Cave 20x20 by Strosahl (on 8. December 2020, 20:54) | 32 | 97 % |
| Quantum-safe sudoku by chameleon (on 26. September 2022, 20:11) | 32 | 91 % |
| Field Lines by mathpesto (on 8. April 2023, 21:10) | 104 | 98 % |
