(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 | |
|---|---|---|---|
 | Inequalities by Ennead (on 31. October 2023, 11:53) | 19 |  98 % |
| Pêcher pour pêches (Killer Sudoku with Same Size Same Sum) by purpl (on 27. April 2024, 23:58) | 20 | 92 % |
| Tom and Jerry by SXH (on 3. December 2024, 06:57) | 17 | 94 % |
| [TSL][S1T6] Across the Stars by The Book Wyrm (on 30. July 2025, 17:07) | 21 | 98 % |
| Siamese Coral (1) by KNT (on 6. March 2023, 02:36) | 49 | 100 % |
| Still no cage totals... - Odd/Even Killer Sudoku (#6) by Mr.Menace (on 14. May 2021, 23:02) | 29 | 96 % |
| Regional Yajilin ('Abandoned Factory') by PixelPlucker (on 17. January 2022, 06:43) | 27 | 97 % |
| [My 100th puzzle] The Secret of 100 by Mad-Tyas (on 5. October 2023, 13:48) | 28 | 97 % |
| Chaos Construction: Nonogram by Xendari (on 8. March 2024, 08:48) | 29 | 97 % |
| Anti-Knight Killer Sudoku - Balanced cages by ahaupt (on 31. May 2020, 22:31) | 44 | 90 % |
| Killers and Palindromes by tenaliraman (on 3. January 2021, 06:45) | 40 | 98 % |
| Paradigm Shift (S-Cell Japanese Sums Cipher) by Agent (on 7. March 2023, 09:00) | 34 | 98 % |
| Colorguru Chaos Deconstruction: Palindromes by crispy16 (on 17. June 2022, 19:42) | 45 | 99 % |
| Firework for Entropy No. 50 by Mad-Tyas (on 19. December 2023, 18:19) | 48 | 95 % |
| Fillmat-doku by yttrio (on 12. January 2024, 21:48) | 40 | 98 % |
| X---V*5 by NurglesGift (on 25. April 2025, 06:00) | 60 | 96 % |
| Yin-yang Anti-Knight by Tom1i (on 30. April 2020, 21:59) | 16 | 96 % |
| Parity sections Sudoku by stephane.bura (on 25. May 2020, 08:35) | 17 | 93 % |
| Two stealth bombers crashing into each other, with tea sandwiches by clover (on 1. December 2020, 20:07) | 26 | 96 % |
| Sumsweeper by Xenonetix (on 9. May 2022, 01:33) | 52 | 96 % |
