(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 | |
|---|---|---|---|
 | Turn up the Heat by GBPack (on 20. July 2021, 02:50) | 24 |  94 % |
| Y Are We Whispering? by glum_hippo (on 18. September 2021, 04:12) | 31 | 95 % |
| Building Blocks by grkles (on 2. February 2022, 04:00) | 31 | 96 % |
| Deconstruction of Whisper Tree (11x11) by SparkNights (on 4. February 2024, 07:05) | 35 | 97 % |
| Nuts and Bolts by KMD (on 15. March 2024, 10:18) | 54 | 95 % |
| Bowser's Castle (Arrow Sudoku) by emmettcito (on 9. April 2021, 12:58) | 93 | 99 % |
| Murder Mystery by 3good5you (on 13. September 2023, 10:39) | 45 | 96 % |
| Nemesis by igniteice (on 3. January 2024, 15:54) | 43 | 91 % |
| ⊕ Deconstructed-RSL-Loop ⊕ by ElChiglia (on 20. April 2024, 07:15) | 44 | 92 % |
| Wichtel 2013 (10): Doppelschlangen-Höhle mit Doppellöwen by wichtel (on 30. May 2014, 10:32) | 26 | 99 % |
| Modular Snakes by Prof.Dori (on 27. October 2023, 09:20) | 33 | 100 % |
| Chaos Construction: X-Sums (9x9) by Jesper (on 21. June 2021, 08:34) | 101 | 96 % |
| Chaos Construction: Internal X-Sums by KNT (on 11. July 2022, 23:23) | 74 | 100 % |
| Cave Akari by Mark Sweep (on 4. December 2020, 10:00) | 51 | 99 % |
| Yin Yang Kropki Sudoku by Phistomefel (on 19. April 2022, 10:24) | 97 | 98 % |
| DIY Arrows by sophmayrob (on 15. June 2023, 07:59) | 49 | 98 % |
| Fractional 10-in-9 killer sudoku by Nylimb (on 2. April 2020, 00:11) | 20 | 95 % |
| Meet The Twins - A Cryptic Anti-King (Little) Killer Sudoku by SirWoezel (on 25. June 2020, 17:13) | 20 | 95 % |
| Fortress of Archers by Mark Sweep (on 26. February 2021, 10:00) | 19 | 92 % |
| Kropkiominos by zetamath (on 30. May 2021, 00:17) | 34 | 97 % |
