(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 | |
|---|---|---|---|
 | Nuts and Bolts by KMD (on 15. March 2024, 10:18) | 54 |  95 % |
| How Bizarre by Nahileon (on 5. June 2024, 14:42) | 39 | 95 % |
| Chaos Construction: X-Sums (9x9) by Jesper (on 21. June 2021, 08:34) | 105 | 96 % |
| Tapa mit Steigerung by berni (on 5. February 2009, 15:07) | 172 | 95 % |
| Murder Mystery [Cipher, Little Killer, Look-and-Say Little Killer] by 3good5you (on 13. September 2023, 10:39) | 46 | 96 % |
| Nemesis by igniteice (on 3. January 2024, 15:54) | 44 | 91 % |
| ⊕ Deconstructed-RSL-Loop ⊕ by ElChiglia (on 20. April 2024, 07:15) | 44 | 92 % |
| 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 % |
| Roman Lockout by Jay Dyer (on 19. February 2022, 23:16) | 19 | 98 % |
| Double fillomino by filuta (on 8. December 2022, 15:38) | 21 | 98 % |
| Irrwisch Sudoku: Sandwich by Gliperal (on 22. May 2023, 11:30) | 37 | 98 % |
| Escalation by Celery (on 12. September 2023, 22:31) | 47 | 94 % |
| Silent Suguru by dennischen (on 27. April 2023, 01:12) | 46 | 99 % |
| Snakes of Chaos by Andrewsarchus (on 14. January 2025, 15:59) | 77 | 99 % |
| Robot Lines by marty_sears (on 18. November 2024, 12:41) | 100 | 96 % |
| Cosmic Cages by yanggang (on 24. July 2024, 23:20) | 28 | 92 % |
| Half Full Jar by Nimo (on 25. February 2025, 10:47) | 29 | 95 % |
| Compass Chaos Construction by Jay Dyer (on 11. March 2023, 20:08) | 61 | 99 % |
