(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 | |
|---|---|---|---|
 | Toroidal Region XY-Sums (Chaos Construction, 8x8) by thoughtbyte (on 15. September 2022, 00:11) | 20 |  98 % |
| Fillomino Pyramid by Myxo (on 26. February 2023, 16:04) | 32 | 97 % |
| Star Killer Part 3: Lunch Break by FischmitFahrrad (on 5. January 2024, 20:00) | 17 | 96 % |
| Star Killer Part 5: Hull Breach by FischmitFahrrad (on 7. January 2024, 20:00) | 18 | 98 % |
| It's a Non-Factor by SSG (on 26. October 2023, 09:24) | 50 | 96 % |
| Jungle Japes [Indexing Killer Sudoku] by wisty (on 30. November 2023, 23:00) | 14 | 96 % |
| Godoku by sfushidahardy (on 25. May 2024, 20:28) | 16 | 94 % |
| Duet (Overlapping Tetrominous Loop) by the_cogito (on 28. June 2024, 22:34) | 13 | 100 % |
| Focus on Symmetry by Mad-Tyas (on 4. October 2024, 10:26) | 47 | 95 % |
| Killomino (Sudoku Fillomino Killer) by purpl (on 21. December 2024, 17:51) | 31 | 98 % |
| Computational Maniac by SXH (on 2. January 2025, 04:54) | 19 | 92 % |
| Hybrid Series #1: Pentominous Mid-Loop by Tyrgannus (on 11. January 2025, 11:32) | 30 | 98 % |
| Cassiopeia (Pentominous/Star Battle) by goodcity (on 21. February 2025, 12:12) | 14 | 98 % |
| 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 % |
| The King's Archers by Lizzy01 (on 16. May 2024, 16:00) | 63 | 93 % |
| 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 % |
| Ambiguous Arrows Sudoku by Jay Dyer (on 25. May 2022, 21:26) | 47 | 96 % |
| Double Fireworks by antiknight (on 9. January 2023, 07:23) | 49 | 94 % |
