(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 | |
|---|---|---|---|
 | Sagittarius (Killer Sudoku ft. jovi_al) by purpl (on 7. October 2022, 01:39) | 80 |  94 % |
| Interval Sums Sudoku by Qodec (on 28. November 2021, 02:08) | 38 | 94 % |
| Two Sums by CaptZebraCakes (on 26. January 2024, 20:57) | 42 | 96 % |
| Peace Dove by Phurba (on 27. August 2024, 00:07) | 126 | 93 % |
| Watchtowers by Belamis (on 6. July 2025, 06:15) | 41 | 93 % |
| Thermo Miracle Sudoku by SudokuExplorer (on 7. July 2020, 18:05) | 102 | 90 % |
| Chaotic counting by palpot (on 16. December 2023, 00:08) | 97 | 96 % |
| Ignition! (Thermo) by Blashyrkh (on 19. October 2024, 14:41) | 116 | 94 % |
| Heavy by zetamath (on 1. January 2026, 22:16) | 130 | 97 % |
| Sudoku Variants Series (351) - Double Trouble Killer Sudoku by Richard (on 15. December 2021, 00:00) | 78 | 96 % |
| Pac-Man Sudoku by mathpesto (on 10. June 2023, 04:50) | 130 | 95 % |
| Parity Runs #3: Skyscraper by Madmahogany (on 10. June 2020, 20:17) | 45 | 94 % |
| Azulejos by ndsurgenor (on 15. March 2022, 14:42) | 36 | 96 % |
| Daedalus by jovi_al (on 18. October 2022, 20:36) | 48 | 90 % |
| Chaos Fillomino - Border Gaps #1 by Mark Sweep (on 7. December 2022, 10:00) | 37 | 99 % |
| Prison Negativity by Prof.Dori (on 30. January 2024, 18:54) | 21 | 90 % |
| Losing Luck by AParliamentofOwls (on 30. October 2025, 20:35) | 23 | 94 % |
| Jello by zetamath (on 1. October 2023, 15:25) | 88 | 93 % |
| Schrödinger 203: Quantum Tunnelling by ViKingPrime (on 30. September 2023, 00:30) | 59 | 97 % |
| Negative X plus V by TheGreatGoatsbie (on 7. August 2024, 20:10) | 116 | 94 % |
