(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 | |
|---|---|---|---|
 | Trident by randall (on 6. January 2023, 23:46) | 18 |  95 % |
| Missing Digits by FryTheGuy (on 15. January 2023, 21:01) | 27 | 94 % |
| Crypto Japanese Cave / Pentominous by KNT (on 26. January 2023, 04:41) | 40 | 99 % |
| Boxes of Paint (Colourful Killers) by The Book Wyrm (on 23. November 2023, 23:18) | 13 | 91 % |
| I.M.A.P.P: Wild Japanese Sum Tapa (12x12) by Playmaker6174 (on 29. January 2024, 22:31) | 23 | 98 % |
| Chaos Construction: 2nd Region Sight Sum (9x9) by Playmaker6174 (on 26. April 2024, 05:30) | 39 | 98 % |
| Bank Vault by mormagli (on 5. June 2024, 19:45) | 20 | 95 % |
| Factorial Cages by Nurator (on 13. August 2024, 10:48) | 13 | 90 % |
| German Whisper Cages by kolot (on 17. March 2022, 19:50) | 65 | 98 % |
| Chaos Construction: Region Counting by KNT (on 28. April 2022, 17:59) | 57 | 94 % |
| Old Maid by ICHTUES (on 5. February 2025, 23:34) | 65 | 98 % |
| Colossal Slitherlink Sudoku by Agent (on 5. September 2023, 09:00) | 54 | 99 % |
| Lockdown by Prof.Dori (on 29. September 2025, 13:12) | 83 | 96 % |
| Rivers and Islands Sudoku #2 (hard) by matt383 (on 27. May 2020, 14:12) | 39 | 96 % |
| Greedy Cages Sudoku by Phistomefel (on 3. May 2022, 22:41) | 75 | 99 % |
| Bharatanatyam (2T1L CC) by Xenonetix (on 13. August 2022, 00:22) | 35 | 97 % |
| The Elephant (Renban, Entropy) by Mad-Tyas (on 3. January 2023, 11:37) | 39 | 97 % |
| X-Sums / Skyscraper Killer Sudoku by KNT (on 16. September 2022, 18:17) | 54 | 98 % |
| Utterly A Maze Thing by fjam (on 12. March 2023, 19:01) | 27 | 95 % |
| Regional Scores by Big Tiger (on 16. December 2023, 13:45) | 30 | 98 % |
