(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 | |
|---|---|---|---|
 | Chaotic Wrogn [Tribute to DiMono] by Undar_Beyond (on 28. December 2020, 08:14) | 77 |  99 % |
| Miracle Clones [Tribute to Botaku] by Undar_Beyond (on 10. November 2020, 20:34) | 26 | 90 % |
| Fission (Classic Thermo) by emmettcito (on 7. May 2021, 12:37) | 23 | 95 % |
| Heart Breaker (Arrow Sudoku) by FryTheGuy (on 27. May 2021, 03:36) | 11 | 90 % |
| Arrow Forest by PotatoHead21 (on 28. September 2021, 09:51) | 12 | 90 % |
| Questionable Chaos (Y-sums / Skyscrapers sums chaos construction) by Lizzy01 (on 30. May 2022, 11:59) | 14 | 95 % |
| Misfits by filuta (on 10. November 2022, 17:30) | 32 | 100 % |
| Afterlife (Yin Yang Fillomino Deconstruction) by Agent (on 15. November 2022, 09:00) | 56 | 100 % |
| Double fillomino by filuta (on 8. December 2022, 15:38) | 13 | 100 % |
| Four Alien Theorem (Build Your Own Killer Sudoku) by Agent (on 7. April 2023, 09:00) | 35 | 99 % |
| Make Room by Jay Dyer (on 5. July 2023, 00:36) | 27 | 96 % |
| A Flock of Pixels (Colourful Killers) by The Book Wyrm (on 27. August 2023, 15:56) | 10 | 98 % |
| Japanese Dominos by KNT (on 14. March 2024, 15:59) | 33 | 99 % |
| Fillomenon by DarthParadox (on 2. October 2023, 19:14) | 94 | 96 % |
| Japanese Sum Cave Cipher #15: Doppelcipher by KNT (on 3. October 2023, 18:10) | 38 | 100 % |
| Trapped by a Killer by SudokuExplorer (on 25. November 2021, 00:00) | 51 | 95 % |
| J-Sum Country Chaos by Cephalo (on 23. June 2023, 10:00) | 20 | 99 % |
| Hysteria by ThePedallingPianist (on 14. April 2024, 04:56) | 22 | 93 % |
| Triple Japasu IV - Pin7guins nightmare by Luigi (on 23. May 2018, 09:22) | 29 | 95 % |
| Candy Corner (ft. grkles) by Niverio (on 10. November 2023, 18:53) | 32 | 93 % |
