(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 | |
|---|---|---|---|
 | Sudoku Variants Series (369) - Killer - Hidden Arrows Sudoku by Richard (on 4. May 2022, 01:00) | 78 |  97 % |
| Floodwaters by Jay Dyer (on 9. July 2022, 00:45) | 73 | 97 % |
| Sashigane Sudoku by Ambrose (on 14. November 2022, 14:06) | 75 | 97 % |
| Japanische Summen-Höhle 2358 by Uhu (on 1. August 2017, 22:32) | 48 | 98 % |
| For A Few Circles More (fillomino) by SkepticalMario (on 31. December 2024, 21:19) | 53 | 95 % |
| Even Trios Killer Sudoku by Quarterthru (on 14. September 2020, 12:00) | 33 | 98 % |
| Short THERM 12+1 by Lisztes (on 13. November 2020, 01:00) | 33 | 90 % |
| BLT by zetamath (on 19. June 2021, 20:30) | 32 | 98 % |
| Irregional by riffclown (on 2. April 2022, 19:21) | 32 | 93 % |
| Prime Party by Realshaggy (on 22. September 2022, 01:17) | 29 | 95 % |
| Variety (6x6 Sudoku Pack) by Florian Wortmann (on 6. June 2024, 12:56) | 35 | 97 % |
| ABENNR by FullDeck-Missing (on 14. November 2024, 06:20) | 73 | 95 % |
| Crossbow Training by Sniglett (on 29. December 2024, 02:18) | 30 | 94 % |
| Shenanigans by Jay Dyer (on 9. May 2023, 17:11) | 172 | 98 % |
| Thermography by arbitrary (on 12. December 2023, 16:22) | 76 | 95 % |
| Counting Reflections by Jolly Rogers (on 18. September 2025, 18:35) | 78 | 95 % |
| Koralle (5) by Uhu (on 8. November 2020, 11:15) | 38 | 91 % |
| Juggernaut by Andrewsarchus (on 23. October 2022, 22:20) | 43 | 92 % |
| Challah by pieguy (on 10. November 2023, 03:30) | 45 | 91 % |
| Mounted Archers by NurglesGift (on 24. October 2025, 20:15) | 45 | 92 % |
