(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 | |
|---|---|---|---|
 | Stretch marks by Qodec (on 23. March 2022, 21:37) | 107 |  98 % |
| Coordinators by mathpesto (on 6. November 2025, 21:41) | 72 | 97 % |
| 2CT Appreciation (German Whispers thermometer sudoku) by Qodec (on 1. January 2024, 23:34) | 94 | 97 % |
| Twin chaos sudoku by Richard (on 21. October 2009, 21:48) | 118 | 93 % |
| Six-pack Linked Puzzles by Genomico (on 17. September 2020, 00:51) | 58 | 97 % |
| The 27 Cage Run by AFrayedKnot (on 24. September 2020, 21:12) | 29 | 92 % |
| GraVitron (by Twototenth and Tallcat) by twototenth (on 25. January 2022, 08:00) | 30 | 97 % |
| Chain Link Fence [Arrow Sudoku] by Malrog (on 25. August 2022, 13:36) | 29 | 93 % |
| De l'autre côté... [9x9 mirrored digits] by Christounet (on 5. September 2023, 08:32) | 54 | 99 % |
| Sleeper Cells by Bearded Fool (on 30. August 2024, 12:00) | 37 | 92 % |
| The Diamond Sea (XY Differences Chaos Construction) by tallcat (on 10. May 2025, 06:00) | 212 | 98 % |
| Naked Filloku (Filloku #2) by mormagli (on 16. September 2023, 14:09) | 50 | 93 % |
| Palindrome Killer by MavericksJD (on 6. January 2021, 11:12) | 26 | 91 % |
| 真笑Puzzles048--Chaos Construction--Su Qin002 by cdwg2000 (on 23. March 2022, 12:24) | 23 | 99 % |
| Battle With The Archers 36 - Dual Puzzles: Directional Intuition by Playmaker6174 (on 24. September 2022, 11:27) | 22 | 95 % |
| Fauteuil by ICHTUES (on 4. December 2022, 06:00) | 23 | 96 % |
| Oil Spill by Mayamor (on 20. April 2023, 14:35) | 28 | 92 % |
| Des Teufels Hufeisen by Kalorienreduziert (on 20. January 2024, 16:03) | 24 | 90 % |
| Counting Calories by marty_sears (on 3. June 2024, 07:30) | 155 | 97 % |
| Taste The Rainbow by Bearded Fool (on 22. November 2024, 12:00) | 27 | 92 % |
