(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 | |
|---|---|---|---|
 | Toutatis by IcyFruit (on 9. May 2024, 14:35) | 46 |  94 % |
| Schrodinger's Split Peas by SamuPiano (on 12. July 2024, 15:44) | 44 | 97 % |
| Knight's Whirlpool by SudokuExplorer (on 10. February 2022, 00:30) | 114 | 98 % |
| Colour Wheel (Colourful Killers, Rotational Pairs) by The Book Wyrm (on 18. May 2024, 00:55) | 35 | 95 % |
| Roundabouts by Black_Doom (on 27. July 2024, 19:36) | 36 | 93 % |
| My Big, Hard, Throbbing Kakuro by clover (on 30. January 2026, 00:27) | 42 | 98 % |
| Tilted And Squished by ChinStrap (on 24. April 2026, 20:02) | 36 | 94 % |
| Century (Counting Circles + Numbered Rooms) by tallcat (on 29. May 2024, 08:00) | 59 | 98 % |
| Too hot to hoot! - A Thermo Palindrome Sudoku by Philipp Huber (on 18. August 2020, 19:39) | 28 | 98 % |
| Tilted Mirror - Palindrome Killer Sudoku by Tyrgannus (on 27. March 2021, 05:26) | 26 | 98 % |
| Surround Set by PrimeWeasel (on 11. February 2022, 12:12) | 22 | 98 % |
| Mirror Mirror by Andrewsarchus (on 18. October 2025, 13:58) | 30 | 94 % |
| Build Your Own Killer: Criminal Mind by Playmaker6174 (on 3. March 2022, 18:07) | 42 | 100 % |
| BYO Kropki Cages by mathpesto (on 10. December 2022, 02:33) | 76 | 99 % |
| LM 2016 - Spätfolgen: Sternenhimmel-Japanische Summen by ibag (on 15. August 2016, 20:13) | 42 | 99 % |
| Broken Secrets by TotallyNormalCat (on 2. June 2021, 07:00) | 66 | 98 % |
| Unbekannte Bahnhöfe by Dandelo (on 13. August 2021, 18:23) | 15 | 100 % |
| Maelstrom by MavericksJD (on 2. June 2023, 02:07) | 34 | 92 % |
| Quicksort by filuta (on 29. June 2023, 14:15) | 13 | 92 % |
| No Mountains Allowed by Laake (on 19. November 2023, 23:52) | 17 | 94 % |
