(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 | |
|---|---|---|---|
 | Killer Sudoku(003) by cdwg2000 (on 4. September 2020, 01:04) | 50 |  98 % |
| Wichtel 2020 (3): Wichtel beim Glühwein by wichtel (on 10. April 2021, 00:22) | 22 | 97 % |
| Tilted Mirror - Palindrome Killer Sudoku by Tyrgannus (on 27. March 2021, 05:26) | 23 | 98 % |
| Remanence by Emphyrio (on 12. October 2021, 04:24) | 34 | 97 % |
| Stairity - Chaos Construction by the_cogito (on 10. August 2022, 03:07) | 84 | 98 % |
| Anti-Arrow by Eclectic_Hoosier (on 12. October 2022, 06:28) | 16 | 93 % |
| Maelstrom by MavericksJD (on 2. June 2023, 02:07) | 29 | 92 % |
| Adventskalender 2023, Türchen 16 - Untergrundangeln by Zzzyxas (on 16. December 2023, 07:00) | 29 | 98 % |
| Sandwich X Circles by ICHTUES (on 8. October 2023, 06:00) | 18 | 92 % |
| Bells by LittleNightmaresLady (on 24. November 2023, 18:17) | 17 | 93 % |
| Round Robin by IcyFruit (on 12. January 2024, 21:24) | 30 | 96 % |
| Build Your Own Nuri-Maze #2: Oddsweeper Square by Myxo (on 26. January 2024, 20:13) | 18 | 93 % |
| Chaos Sandwich by Bert (on 24. February 2024, 16:36) | 53 | 93 % |
| Sea Level Rise Sudoku by MagnusJosefsson (on 31. March 2024, 18:58) | 17 | 98 % |
| Century (Counting Circles + Numbered Rooms) by tallcat (on 29. May 2024, 08:00) | 51 | 98 % |
| Orbicular by egubachu (on 12. May 2024, 20:37) | 17 | 93 % |
| Ripples by the_cogito (on 6. September 2024, 17:54) | 11 | 90 % |
| Blemish [Even Squares, Kropki, Renban] by 3good5you (on 22. December 2024, 17:47) | 14 | 90 % |
| A Little Mouthful (Short Sandwiches Sudoku) by Qodec (on 17. January 2025, 23:01) | 32 | 94 % |
| Chequered Arromino #2 by Phistomefel (on 25. May 2023, 20:32) | 100 | 98 % |
