(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 | |
|---|---|---|---|
 | 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) | 36 | 92 % |
| Counting Calories by marty_sears (on 3. June 2024, 07:30) | 147 | 97 % |
| Mysterious Mirrors by marty_sears (on 25. October 2025, 23:49) | 120 | 95 % |
| 3etweeN by Qodec (on 17. April 2021, 17:56) | 80 | 98 % |
| Pointer Arrow Parity Loop by yttrio (on 31. May 2025, 01:42) | 104 | 98 % |
| Twin chaos sudoku by Richard (on 21. October 2009, 21:48) | 116 | 93 % |
| Past Midnight by Selsted (on 20. October 2020, 17:57) | 24 | 97 % |
| 13 by Phurba (on 13. December 2020, 15:59) | 29 | 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) | 22 | 99 % |
| Parcae by Kafkapharnaum (on 20. August 2022, 18:18) | 25 | 97 % |
| Fauteuil by ICHTUES (on 4. December 2022, 06:00) | 23 | 96 % |
| Oil Spill by Mayamor (on 20. April 2023, 14:35) | 28 | 92 % |
| Extra Tall Skyscrapers by yttrio (on 4. August 2023, 20:04) | 47 | 95 % |
| Des Teufels Hufeisen by Kalorienreduziert (on 20. January 2024, 16:03) | 24 | 90 % |
| Taste The Rainbow by Bearded Fool (on 22. November 2024, 12:00) | 27 | 92 % |
| Lie-rises (Flinty Collab) by palpot (on 31. December 2024, 20:15) | 21 | 95 % |
