(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 | |
|---|---|---|---|
 | Looping Chaos by Paletron (on 12. March 2024, 20:44) | 78 |  95 % |
| Modulenburg by RockyRoer (on 14. June 2025, 13:13) | 91 | 95 % |
| Shy Evens X Odds Sudoku by ICHTUES (on 7. February 2021, 06:00) | 54 | 96 % |
| Snowflake by kuraban (on 31. December 2021, 00:38) | 30 | 98 % |
| Arr Arr (Doubler Arrow) by ICHTUES (on 14. August 2022, 06:00) | 58 | 97 % |
| Doggo Adventure #11 by waffles_the_dog (on 9. February 2023, 10:56) | 33 | 91 % |
| Little Killer Around You by Ridhwan (on 19. November 2023, 03:40) | 27 | 94 % |
| Monster Muddle by Md88keys (on 29. August 2025, 07:04) | 32 | 90 % |
| Sudoku Variants Series (332) - Teleportation Cycle Sums Sudoku by Richard (on 4. August 2021, 00:00) | 82 | 97 % |
| 真笑Puzzles040--Chaos Construction-- “孙子” 002 by cdwg2000 (on 19. May 2021, 14:59) | 27 | 99 % |
| Red Colour by apiyo (on 16. April 2022, 14:02) | 32 | 95 % |
| Why Did It Have To Be Snakes? by DadJokes (on 7. September 2022, 18:41) | 33 | 96 % |
| Electrostatic Discharge by Allagem (on 14. April 2024, 11:30) | 64 | 93 % |
| Diamonds are Forever by Sartor (on 24. November 2025, 16:26) | 76 | 93 % |
| Pentomino-Hitori by tyskhubi (on 2. August 2014, 09:41) | 31 | 94 % |
| Hidden X-Sums & Sandwiches by BL00DW0LF (on 7. August 2020, 05:39) | 32 | 91 % |
| Killer X Sudoku by ICHTUES (on 9. May 2021, 06:00) | 60 | 95 % |
| Squeez Theorem (Suguru Deconstruction) by KevinTheMH (on 28. June 2023, 21:33) | 34 | 94 % |
| Arrows Accord by graggle (on 8. February 2025, 13:00) | 41 | 92 % |
| Vendetta by NicoD (on 14. December 2025, 05:30) | 38 | 96 % |
