(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 | |
|---|---|---|---|
 | Mambo by zetamath (on 6. September 2024, 00:16) | 42 |  96 % |
| Loopy Circles by Scojo (on 9. September 2025, 22:33) | 77 | 98 % |
| Confluence 2: Dumediat Birthday Edition by mathpesto (on 31. August 2023, 17:41) | 66 | 100 % |
| Haywire by mathpesto (on 5. September 2024, 22:21) | 47 | 97 % |
| Glückwünsche vom Orion by Statistica (on 9. July 2019, 00:55) | 25 | 100 % |
| Antiknight Killer Sudoku 2 by PotatoHead21 (on 6. November 2022, 01:25) | 32 | 91 % |
| Arrows by psninn (on 13. May 2024, 13:03) | 30 | 92 % |
| Gross Misconduct by marty_sears (on 20. July 2025, 01:00) | 203 | 97 % |
| Near Algodones (Full Rank Sudoku) by SamuPiano (on 11. August 2025, 15:44) | 27 | 96 % |
| Haphazard by NicoD (on 3. September 2025, 05:30) | 35 | 96 % |
| Mercury Arrows (Thermo Arrow) by tallcat (on 23. May 2021, 23:22) | 35 | 94 % |
| Anarchery by Kaktuslav (on 5. August 2025, 08:00) | 39 | 96 % |
| Six-pack Linked Sudokus #8 by Genomico (on 15. September 2021, 04:10) | 46 | 99 % |
| Rätselkombi by Luigi (on 19. July 2010, 13:10) | 60 | 94 % |
| Think Outside the Box by Frippe (on 8. April 2024, 20:33) | 79 | 92 % |
| RAT RUN 22: Copyrat by marty_sears (on 21. January 2026, 03:35) | 407 | 98 % |
| More by TotallyNormalCat (on 4. September 2021, 22:30) | 81 | 98 % |
| Frankenstein by zetamath (on 10. June 2025, 20:50) | 85 | 95 % |
| Gerade Ungerade TaKo by tuace (on 22. March 2014, 10:30) | 45 | 98 % |
| Quintuple skyscrapers by zorant (on 6. December 2019, 12:20) | 30 | 95 % |
