(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 | |
|---|---|---|---|
 | Shapes without Shapes by zetamath (on 2. March 2021, 04:28) | 43 |  94 % |
| Space Battle by Jeet Sampat (on 14. September 2021, 04:38) | 19 | 93 % |
| Whirlpool by Jay Dyer (on 8. October 2021, 21:23) | 24 | 90 % |
| Aad-van-ced Irregularity by crispy16 (on 14. May 2022, 05:49) | 21 | 91 % |
| Little Talks 2 by djorr (on 8. August 2022, 14:00) | 19 | 93 % |
| Three is a Crowd Sudoku #2 by Genomico (on 27. September 2022, 20:55) | 18 | 100 % |
| ∞ Interfering Loops ∞ by ElChiglia (on 18. October 2023, 18:37) | 39 | 97 % |
| Penpalindromes Are Numbered One by cygne (on 31. January 2026, 17:45) | 22 | 91 % |
| Symmetrien 7 by julius64 (on 25. June 2011, 00:07) | 72 | 95 % |
| Wichtel 2016 (5): Stallungen am Nordpol by wichtel (on 12. June 2017, 22:00) | 33 | 96 % |
| German Sandwiches by Scruffamudda (on 16. March 2022, 07:34) | 41 | 98 % |
| Degraded Cells (Juggler Impression) by gdc (on 9. September 2024, 18:15) | 41 | 96 % |
| Endemic by NicoD (on 13. February 2026, 05:30) | 42 | 93 % |
| Temperamental Triplets by rockratzero (on 16. September 2022, 17:34) | 65 | 96 % |
| Constellation Sudoku by Gliperal (on 29. August 2020, 10:08) | 20 | 93 % |
| Build Your Own Anti-Knight Sudoku by DiMono (on 24. October 2020, 17:41) | 20 | 94 % |
| Leapfrog Sudoku by stephane.bura (on 3. December 2020, 20:00) | 19 | 97 % |
| Whirlpool by Xailran (on 20. September 2021, 13:04) | 17 | 91 % |
| Dumbbells by djorr (on 29. March 2022, 14:00) | 23 | 97 % |
| Pieces of the Puzzle by grkles (on 22. February 2022, 01:39) | 21 | 99 % |
