(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 | |
|---|---|---|---|
 | How Bizarre by Nahileon (on 5. June 2024, 14:42) | 37 |  95 % |
| Four Colour Theorem by Jay Dyer (on 19. March 2022, 13:12) | 103 | 97 % |
| Thermo Space Force by PotatoHead21 (on 31. May 2021, 03:51) | 39 | 95 % |
| Recurring Nightmares by Jay Dyer (on 16. October 2022, 01:00) | 38 | 97 % |
| Little Kropkiller by Mark Sweep (on 13. November 2020, 10:00) | 37 | 95 % |
| California skyscraper sudoku by Shinya (on 12. May 2021, 09:02) | 15 | 93 % |
| Killer Shikoku by the_cogito (on 9. March 2022, 00:16) | 56 | 98 % |
| Unendliches Höhlenrätsel (Infinity Cave) by Phistomefel (on 3. April 2023, 20:00) | 23 | 92 % |
| Wichtel 2017 (12 und Schluss): Geteilte U-Bahn by wichtel (on 24. December 2018, 10:04) | 31 | 99 % |
| Ocean by kolot (on 15. August 2021, 07:58) | 34 | 97 % |
| The Devil's Cage by TinkerTroy (on 3. October 2022, 18:36) | 33 | 96 % |
| Killocator by starwarigami (on 27. October 2021, 10:15) | 52 | 98 % |
| Japanische Höhle vom Hein mit Hilfe vom Irrwisch (2) by ibag (on 20. April 2020, 00:00) | 27 | 100 % |
| Arrow Logic by PotatoHead21 (on 17. May 2021, 21:03) | 14 | 94 % |
| Wichtel 2021 (2): Der Sternenkompass by wichtel (on 1. June 2022, 21:20) | 14 | 100 % |
| Arrow Jungle by PotatoHead21 (on 18. August 2023, 11:49) | 17 | 92 % |
| What's in a naname? (Nanameguri/Killer) by dumediat (on 7. September 2023, 22:51) | 15 | 98 % |
| Rhizome (Fillomino/Landvermessung/Irrwisch) by dumediat (on 13. September 2023, 13:06) | 14 | 96 % |
| Blue Lightning by LittleNightmaresLady (on 25. September 2023, 18:14) | 16 | 90 % |
| Bullet Bill (Region-Sum Lines) by LittleNightmaresLady (on 24. January 2024, 18:14) | 17 | 92 % |
