(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 | |
|---|---|---|---|
 | Zeroth Law of Chromodynamics by twototenth (on 26. April 2021, 13:08) | 94 |  97 % |
| Revenge of the Hash (Irregular Thermo Sudoku) by lavaloid (on 9. May 2021, 11:00) | 14 | 92 % |
| Even Hunter by Lisztes (on 16. October 2021, 01:00) | 22 | 92 % |
| 159 Shards by Qodec (on 22. September 2021, 12:36) | 87 | 93 % |
| Key Word (feat. Playmaker6174) by purpl (on 19. October 2021, 17:45) | 19 | 97 % |
| Line of Sight Chaos Production by RockyRoer (on 29. January 2022, 03:39) | 65 | 99 % |
| X-Sums: 37 by the_cogito (on 1. February 2022, 16:58) | 15 | 98 % |
| Knuckle O'Sandwich by zegres (on 13. April 2022, 06:33) | 35 | 96 % |
| Section 8 by XeonRisq (on 16. June 2022, 01:00) | 33 | 95 % |
| Hungarian Tapa / Roller Coaster (1) by KNT (on 23. September 2022, 20:45) | 66 | 100 % |
| Wichtel 2021 (11): Eine neue Route durch das schöne Rätselhausen by wichtel (on 22. November 2022, 10:22) | 13 | 100 % |
| Thermo Yin Yang by oklux (on 10. October 2022, 19:44) | 49 | 96 % |
| Rudolph? by ThePedallingPianist (on 22. November 2022, 23:38) | 74 | 96 % |
| Snake Nest Sudoku (chaos construction) by Al Fresco (on 9. December 2022, 20:47) | 27 | 96 % |
| Growing Up by the_cogito (on 22. December 2022, 19:43) | 44 | 99 % |
| Parity Party XXVI, "Silly String" by glum_hippo (on 7. January 2023, 15:26) | 16 | 90 % |
| Thermollominologically (Fillomino/Thermo) by dumediat (on 12. January 2023, 00:00) | 58 | 95 % |
| Slingin' Sammies by mnasti2 (on 20. January 2023, 10:33) | 31 | 99 % |
| 23 Renban by Florian Wortmann (on 8. February 2023, 19:32) | 106 | 97 % |
| Bermuda Triangle by XeonRisq (on 3. May 2023, 04:00) | 22 | 90 % |
