(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 : Wrogn by lerroyy (on 8. June 2022, 20:59) | 73 |  98 % |
| Chaos Construction: Regional Chess Sums by Nordy (on 7. January 2022, 08:00) | 16 | 96 % |
| Japanese Nurikabe (2) by KNT (on 6. September 2022, 02:52) | 61 | 100 % |
| Count the Borders by Tobias Brixner (on 21. January 2023, 20:18) | 16 | 90 % |
| Japanese Sums #2: Killer Cages Fillomino by lerroyy (on 3. March 2023, 14:29) | 16 | 98 % |
| J-Sum Country Chaos by Cephalo (on 23. June 2023, 10:00) | 29 | 98 % |
| ABC-Box Hybrid 2: Numbered Room (12x12) by Playmaker6174 (on 8. July 2024, 12:30) | 19 | 100 % |
| Camera Obscura (Odd-Even Coded Teleportation Cycle Sums Sudoku) by Feadoor (on 4. August 2025, 09:29) | 16 | 90 % |
| Welcome to Chaconopia (Chaos Construction) by Mad-Tyas (on 16. August 2025, 13:24) | 19 | 96 % |
| DDDDoppelgänger by mellowrobinson (on 12. December 2025, 19:19) | 34 | 100 % |
| Invisible Killers by yttrio (on 10. March 2023, 21:32) | 47 | 95 % |
| Afterlife (Yin Yang Fillomino Deconstruction) by Agent (on 15. November 2022, 09:00) | 70 | 98 % |
| Serial Duplex by Jay Dyer (on 29. October 2022, 17:46) | 38 | 98 % |
| Gin (11x11 Deconstruction) by lerroyy (on 13. November 2022, 23:51) | 27 | 99 % |
| Multi-sudoku: Orb 2 by DiMono (on 23. April 2021, 07:58) | 30 | 97 % |
| Even Small Prime by FryTheGuy (on 13. December 2021, 16:28) | 29 | 99 % |
| Archery Target by Nahileon (on 24. April 2022, 15:48) | 43 | 97 % |
| Manhattan by wooferzfg (on 17. August 2023, 02:49) | 27 | 98 % |
| Doppelcrypto Japanese Cave by KNT (on 3. October 2023, 18:10) | 50 | 97 % |
| Cryptic Shaders by wooferzfg (on 27. January 2024, 09:27) | 12 | 100 % |
