(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 | |
|---|---|---|---|
 | Japanische Bahnhöfe, Teil 2 by pirx (on 27. May 2020, 13:00) | 26 |  99 % |
| Open Face Apple by pieguy (on 7. August 2023, 22:49) | 30 | 90 % |
| Top Floor by ThePedallingPianist (on 7. January 2026, 01:20) | 27 | 95 % |
| U-Bahn mit Haltestellen III by tuace (on 28. March 2016, 16:22) | 47 | 95 % |
| Temperature (Thermo, Entropy) by Mad-Tyas (on 30. January 2023, 08:22) | 55 | 94 % |
| Irrwisch Sudoku: Sandwich by Gliperal (on 22. May 2023, 11:30) | 50 | 99 % |
| Cave Fillomino #1 (10x10) by Jesper (on 29. August 2020, 11:40) | 79 | 100 % |
| Wichtel 2016 (12 und Schluss): Unterirdische Katakomben mit Kerzenbeleuchtung by wichtel (on 12. October 2017, 21:01) | 26 | 98 % |
| Escape Velocity (Arrow/XV) by damo_89 (on 3. June 2025, 22:53) | 66 | 95 % |
| Tenuity (Japanese sums/Pentomino chain) by dumediat (on 14. September 2025, 15:03) | 28 | 100 % |
| Diamond Rank by Andrewsarchus (on 20. January 2026, 07:39) | 28 | 96 % |
| 4-color killer sudoku #2 by Nylimb (on 3. April 2021, 04:45) | 116 | 99 % |
| Rundweg Family Photo by pokerke (on 14. February 2011, 00:57) | 83 | 99 % |
| Implications of Parity by Niverio (on 30. July 2022, 13:06) | 55 | 98 % |
| Who Knows Where the Time Goes by juggler (on 28. December 2024, 07:50) | 63 | 96 % |
| Ma'at's Transcript: Order from Chaos (Chaos Construction) by Chilly (on 13. July 2022, 13:07) | 91 | 100 % |
| Chained killer sudoku no. 3 by Shinya (on 23. August 2021, 22:33) | 26 | 99 % |
| Flaschenpost (Nurikabe Cipher Sudoku) by Agent (on 4. October 2022, 09:00) | 60 | 99 % |
| Stroopwafel by pieguy (on 19. October 2023, 23:13) | 29 | 92 % |
| Feeling Six Yet? by oskode (on 27. August 2025, 06:06) | 30 | 93 % |
