(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 | |
|---|---|---|---|
 | Parity Paradigm by grkles (on 31. December 2021, 13:42) | 26 |  99 % |
| Post Office Panic! by tesseralis (on 4. July 2022, 10:14) | 86 | 98 % |
| Chaos Sum-dok-U-Bahn by Christounet (on 9. December 2024, 08:07) | 28 | 99 % |
| BERLIN - Buchstabenrätsel / Letter Puzzle by DocLogic (on 2. February 2025, 17:57) | 26 | 95 % |
| Asterias (Pentopia U-Bahn) by MaizeGator (on 22. July 2025, 05:19) | 29 | 96 % |
| Counting Sum Dots by Andrewsarchus (on 24. January 2026, 19:11) | 31 | 95 % |
| Chaotic Archery - Chaos Construction Sudoku by Mr.Menace (on 12. May 2022, 22:51) | 74 | 97 % |
| Perfectly Average Killers by Tacosian (on 14. March 2023, 03:13) | 44 | 94 % |
| Chaos Sandwich by Bert (on 24. February 2024, 16:36) | 61 | 94 % |
| 真笑Puzzles007:Bachelor(光棍) Sudoku02 by cdwg2000 (on 23. December 2020, 22:43) | 16 | 92 % |
| Stepping Stones by RockyRoer (on 2. October 2021, 15:00) | 30 | 98 % |
| 100 by EricRathbun (on 25. September 2022, 22:50) | 18 | 92 % |
| Réaltraí (Pentominous spiral galaxies/Fillomino) by dumediat (on 27. January 2024, 20:19) | 51 | 100 % |
| Total Chaos by Bert (on 5. June 2024, 18:32) | 31 | 98 % |
| Norinori Killer Sudoku by SudokuExplorer (on 9. February 2021, 01:00) | 80 | 96 % |
| Liar Japanese Sums #3: Renban Square by Niverio (on 8. January 2023, 21:45) | 67 | 98 % |
| Charybdis by Gliperal (on 21. March 2021, 05:46) | 52 | 97 % |
| XV Sandwiches by RockyRoer (on 21. November 2020, 04:47) | 34 | 95 % |
| Build Your Own Aquarium by wooferzfg (on 5. February 2022, 16:54) | 37 | 99 % |
| Ring Loop by Prof.Dori (on 29. September 2024, 02:09) | 33 | 94 % |
