(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 | |
|---|---|---|---|
 | [PAC] Cipher JS Clone Sudoku by TVDK (on 20. September 2025, 13:56) | 30 |  95 % |
 | the maharajah of pookajee by aqjhs (on 9. May 2026, 02:00) | 17 | 100 % |
| Roller Coaster mit Extras 7 by Uhu (on 25. June 2018, 15:32) | 59 | 97 % |
| Killer Cave by udukos (on 7. October 2021, 06:12) | 59 | 100 % |
| Escalation by Celery (on 12. September 2023, 22:31) | 53 | 94 % |
| Murder Mystery [Cipher, Little Killer, Look-and-Say Little Killer] by 3good5you (on 13. September 2023, 10:39) | 49 | 96 % |
| Ambiguity (X-Sums/Numbered Rooms) by udukos (on 5. July 2022, 13:25) | 68 | 97 % |
| violently nostalgic by aqjhs (on 7. July 2025, 07:07) | 73 | 99 % |
| Thermo + Killer + Anti-Knight by stimim (on 30. July 2020, 17:38) | 103 | 98 % |
| Foghqwhgads by ThePedallingPianist (on 9. February 2023, 23:55) | 73 | 96 % |
| Nuts and Bolts by KMD (on 15. March 2024, 10:18) | 57 | 95 % |
| Lines of Time by RandyDan (on 11. February 2026, 18:37) | 32 | 95 % |
| Thermo Space Force by PotatoHead21 (on 31. May 2021, 03:51) | 44 | 95 % |
| Index-istential Crisis (with ChinStrap) by sujoyku (on 19. January 2025, 13:39) | 45 | 97 % |
| Chaos All Over by wuc (on 12. April 2025, 11:49) | 84 | 95 % |
| Propellers by fritzdis (on 6. March 2021, 15:35) | 57 | 97 % |
| Kropkiflotte auf hoher See II by Luigi (on 30. October 2014, 13:51) | 14 | 93 % |
| Cyclic Thermo Sudoku by trivial171 (on 29. April 2020, 03:43) | 15 | 93 % |
| Tangled Arrows (Arrow sudoku) by Aspartagcus (on 23. October 2020, 23:32) | 16 | 95 % |
| Killocator by starwarigami (on 27. October 2021, 10:15) | 59 | 98 % |
