(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 | |
|---|---|---|---|
 | Schlingerpfad 000217 by adam001 (on 3. July 2012, 21:25) | 14 |  92 % |
| Killer Raute by tuace (on 12. January 2014, 15:30) | 45 | 98 % |
| Kropki'd X-sums sudoku by Nylimb (on 3. November 2020, 02:50) | 30 | 95 % |
| Flying 9s by abed hawila (on 18. December 2020, 19:59) | 18 | 92 % |
| Parity Party XVIII, "Clones" by glum_hippo (on 11. April 2021, 06:00) | 14 | 98 % |
| Knights of Parity by Fafrd (on 27. May 2022, 06:38) | 17 | 96 % |
| Between the Lines (Entropic Lines/Between Lines/Kropki Pairs) by dumediat (on 28. August 2022, 17:43) | 20 | 93 % |
| Killer on the Orient Express by ThePedallingPianist (on 9. December 2022, 19:00) | 48 | 97 % |
| Turkish Art: Painting Arrows (CTC Secret Santa 2022) by Niverio (on 27. December 2022, 02:29) | 31 | 100 % |
| Intersection by ralphwaldo1 (on 3. January 2023, 02:44) | 16 | 96 % |
| Demolition (Numbered Rooms, Skyscraper) by Crusader175 (on 15. January 2023, 15:00) | 16 | 92 % |
| Guidelines by DarthParadox (on 3. July 2023, 08:11) | 17 | 96 % |
| TEQUILA - Buchstabenrätsel / Letter Puzzle by DocLogic (on 13. January 2024, 15:46) | 28 | 98 % |
| Islands 4: Chaos Theory by SamuPiano (on 13. March 2024, 20:00) | 14 | 94 % |
| Domino Reduction by Calesch (on 30. July 2024, 19:09) | 16 | 92 % |
| Läufer Loop by Prof.Dori (on 23. September 2024, 12:17) | 31 | 99 % |
| Counting Thermos by Scojo (on 17. December 2023, 21:16) | 116 | 98 % |
| WSC-Training: Clueless Hidden Classic by JonaS2010 (on 7. October 2019, 18:33) | 59 | 98 % |
| K2 (Anti-diagonal arrow sudoku) by Qodec (on 28. October 2023, 17:22) | 66 | 97 % |
| Gravity by jovi_al (on 19. May 2021, 19:16) | 112 | 97 % |
