(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 | |
|---|---|---|---|
 | Smelly Peas by MathGuy_12 (on 13. November 2025, 01:43) | 12 |  90 % |
| Why-Why? by SennyK (on 22. November 2025, 17:15) | 15 | 95 % |
| German Whisper Cages by kolot (on 17. March 2022, 19:50) | 63 | 98 % |
| Chaos Construction: Region Counting by KNT (on 28. April 2022, 17:59) | 57 | 94 % |
| Colossal Slitherlink Sudoku by Agent (on 5. September 2023, 09:00) | 54 | 99 % |
| Rivers and Islands Sudoku #2 (hard) by matt383 (on 27. May 2020, 14:12) | 39 | 96 % |
| 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) | 38 | 97 % |
| Lockdown by Prof.Dori (on 29. September 2025, 13:12) | 75 | 98 % |
| 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 % |
| Medieval Upheaval 4 by Nordy (on 24. June 2024, 08:00) | 84 | 97 % |
| Parity Party X - "Sir Launcelot" by glum_hippo (on 7. June 2020, 06:52) | 22 | 92 % |
| Spiral Galaxy Sudoku with clues by PrimeWeasel (on 13. November 2021, 16:55) | 20 | 97 % |
| Binary Quantum Void by DadJokes (on 13. October 2022, 19:14) | 26 | 94 % |
| I.M.A.P.P: Wild Japanese Sum Tapa (12x12) by Playmaker6174 (on 29. January 2024, 22:31) | 22 | 97 % |
| Chaconopia: Intro 9x9 (Chaos Construction) by Mad-Tyas (on 12. August 2025, 13:54) | 22 | 100 % |
| Killomino Sudoku by Phistomefel (on 10. June 2021, 03:54) | 91 | 99 % |
| Blackadder by udukos (on 30. May 2022, 12:14) | 54 | 97 % |
