(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 | |
|---|---|---|---|
 | Ichidoku [Ichimaga/Sudoku Hybrid, Region Sum Lines] by Malrog (on 29. September 2023, 18:45) | 13 |  98 % |
| DIY Arrows by sophmayrob (on 15. June 2023, 07:59) | 50 | 98 % |
| High f**e! by filuta (on 30. March 2022, 15:29) | 44 | 96 % |
| Two stealth bombers crashing into each other, with tea sandwiches by clover (on 1. December 2020, 20:07) | 25 | 96 % |
| Sumsweeper by Xenonetix (on 9. May 2022, 01:33) | 48 | 96 % |
| Prism Redux by SeaOtter417 (on 2. November 2022, 15:47) | 32 | 91 % |
| Bowser's Castle (Arrow Sudoku) by emmettcito (on 9. April 2021, 12:58) | 95 | 99 % |
| #sudoku by matt383 (on 26. October 2021, 21:08) | 34 | 96 % |
| Siamese Coral (1) by KNT (on 6. March 2023, 02:36) | 48 | 100 % |
| Foghqwhgads by ThePedallingPianist (on 9. February 2023, 23:55) | 66 | 95 % |
| Four By Four by IcyFruit (on 29. February 2024, 17:13) | 56 | 95 % |
| Killer Construction by ahaupt (on 12. June 2020, 21:33) | 63 | 99 % |
| Skyscraper^2 Sudoku by Prasanna16391 (on 5. August 2020, 13:47) | 23 | 99 % |
| Encaged Kropki #2 - oops! no cage totals! by RockyRoer (on 21. October 2020, 00:00) | 21 | 99 % |
| Building Blocks by grkles (on 2. February 2022, 04:00) | 32 | 96 % |
| Bushido (Star Battle Japanese Sums Fillomino) by Agent (on 6. December 2022, 09:00) | 41 | 99 % |
| SC24 - Region Sum Lines 2 by kuraban (on 22. November 2022, 19:33) | 32 | 92 % |
| Battle With The Archers 41: The Fate of Three Worlds by Playmaker6174 (on 9. October 2023, 10:01) | 53 | 96 % |
| Deconstruction of Whisper Tree (11x11) by SparkNights (on 4. February 2024, 07:05) | 35 | 97 % |
| Chaos Construction: Nonogram by Xendari (on 8. March 2024, 08:48) | 23 | 96 % |
