(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 | |
|---|---|---|---|
 | 10-in-9 CLXVI sudoku by Nylimb (on 21. October 2020, 20:10) | 15 |  94 % |
| Primality Party by abed hawila (on 12. March 2021, 15:44) | 13 | 96 % |
| Palindrome Sandwiches by RockyRoer (on 13. March 2021, 12:26) | 28 | 100 % |
| XY-Differences and -Sums by glum_hippo (on 30. April 2021, 06:00) | 17 | 98 % |
| Four Killer Winds by Franjo (on 24. May 2021, 18:49) | 14 | 96 % |
| Jigsaw by PotatoHead21 (on 20. June 2021, 19:54) | 20 | 92 % |
| Two's Company by apiyo (on 11. September 2021, 05:52) | 16 | 94 % |
| Archer's Prologue: Positive Mindset by Playmaker6174 (on 13. November 2021, 06:05) | 58 | 98 % |
| Minesweeper Sudoku by Niverio (on 24. November 2021, 23:53) | 40 | 98 % |
| Classic-style Killer Sudoku by Jeet Sampat (on 27. January 2022, 22:59) | 29 | 94 % |
| The Andromeda Chain (Spiral Galaxies, Lockout Lines) by Chilly (on 8. February 2022, 16:08) | 13 | 98 % |
| Magix by oklux (on 21. February 2022, 18:40) | 16 | 94 % |
| Fifth Amendment (Killer Diagonal Sudoku) by Agent (on 4. March 2022, 09:00) | 36 | 96 % |
| Cyclotron by starwarigami (on 13. March 2022, 11:36) | 21 | 90 % |
| Forked by Emphyrio (on 11. April 2022, 17:57) | 17 | 92 % |
| Gossip Circle by mormagli (on 5. June 2022, 23:52) | 41 | 98 % |
| Piatato's challenge by filuta (on 2. July 2022, 18:01) | 24 | 94 % |
| The Grand Design (Numbered Room combo) by Playmaker6174 (on 27. July 2022, 05:54) | 21 | 94 % |
| Chaos Construction: Renbans by XeonRisq (on 11. August 2022, 05:00) | 53 | 93 % |
| Cliques by purpl (on 22. August 2022, 22:40) | 24 | 92 % |
