(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 | |
|---|---|---|---|
 | Meinsweeper by fjam (on 24. June 2024, 20:01) | 18 |  92 % |
| Chromosomes by ThePedallingPianist (on 3. January 2023, 01:15) | 101 | 96 % |
| Kill Kill (Doubler Killer) by ICHTUES (on 28. August 2022, 06:00) | 55 | 97 % |
| 195? 519? 951? by twototenth (on 20. September 2022, 08:00) | 55 | 97 % |
| String Quartet by IcyFruit (on 5. November 2023, 01:26) | 66 | 96 % |
| Summation U-Bahn Cipher by Agent (on 3. October 2023, 09:00) | 35 | 100 % |
| Wheel of Fortune by Qodec (on 4. September 2020, 13:34) | 22 | 94 % |
| Splatter by PotatoHead21 (on 23. July 2021, 03:35) | 43 | 91 % |
| Hangover by Realshaggy (on 13. February 2022, 17:03) | 39 | 97 % |
| [159] The Sum of All Indexing by W1DEMAN (on 9. November 2022, 09:59) | 21 | 97 % |
| Perfectly Average Killers by Tacosian (on 14. March 2023, 03:13) | 40 | 93 % |
| Centroid by DarthParadox (on 24. May 2024, 17:57) | 19 | 91 % |
| Chaotic Archery - Chaos Construction Sudoku by Mr.Menace (on 12. May 2022, 22:51) | 65 | 97 % |
| Messier 43 (Galaxy Region Sum Lines) by purpl (on 1. October 2022, 01:31) | 60 | 99 % |
| Summenbild mit Lücken by Calavera (on 1. September 2009, 02:51) | 66 | 96 % |
| Cageless (X) Killer Sudoku no. 2 by Shinya (on 23. March 2020, 12:58) | 23 | 95 % |
| Compass Sudoku by stephane.bura (on 16. July 2020, 14:54) | 24 | 97 % |
| Negatively Constrained Slingshot Sudoku by stephane.bura (on 6. August 2020, 20:00) | 24 | 92 % |
| Biloxi - a Beachcomber Sudoku by glum_hippo (on 23. November 2023, 02:00) | 21 | 97 % |
| ABC-Box Hybrid 1.2: A Beautiful Cave (12x12) by Playmaker6174 (on 10. June 2024, 08:30) | 22 | 100 % |
