(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 | |
|---|---|---|---|
 | Wichtel 2017 (10): Luftige Flotte an Wolkenmousse in inversem Schneegestöber by wichtel (on 17. October 2018, 07:04) | 23 |  99 % |
| Wichtel 2021 (5): Fehlkommunikation by wichtel (on 12. August 2022, 20:21) | 22 | 99 % |
| Time by lerroyy (on 13. January 2023, 19:26) | 18 | 91 % |
| Crusties ("Indexed Fives") by RockyRoer (on 21. July 2023, 20:01) | 40 | 96 % |
| Balanced Ride (Roller Coaster/Cave) by Piatato (on 23. October 2023, 11:00) | 31 | 99 % |
| Miami Zipper by Prof.Dori (on 4. February 2024, 16:05) | 52 | 93 % |
| Aqropolis [Aqre Loop Japanese Sums Deconstruction] by Christounet (on 14. May 2024, 00:43) | 17 | 100 % |
| Foggy foggy x-sums by sanabas (on 26. July 2024, 07:36) | 35 | 93 % |
| The Barrel (Arrow Sudoku) by tallcat (on 18. April 2021, 05:29) | 80 | 100 % |
| Pfeilchenbeet / Arrow Farm by Phistomefel (on 17. November 2020, 20:01) | 47 | 99 % |
| Hochhäuser mit Kellern, Teil 3 by pirx (on 3. July 2015, 18:00) | 34 | 99 % |
| Chaos Loop by wooferzfg (on 1. December 2022, 05:49) | 34 | 98 % |
| Unboxing by mathpesto (on 11. May 2023, 05:11) | 64 | 97 % |
| X-sums Killer Sudoku by udukos (on 4. October 2020, 04:28) | 29 | 98 % |
| Giant Tapa by wooferzfg (on 25. February 2024, 04:22) | 28 | 95 % |
| Crypto Japanese Slitherlink by KNT (on 12. November 2022, 22:43) | 48 | 100 % |
| Unsichtbar Hochhauschaos by Luigi (on 22. November 2010, 12:54) | 36 | 95 % |
| Zweiter Pfeilchenstrauß by glum_hippo (on 24. August 2020, 17:26) | 22 | 93 % |
| Broken Gift (Partial Irregular Killer Sudoku) by peterchayward (on 16. May 2021, 11:42) | 39 | 92 % |
| Thermo Battle by 10feet (on 18. February 2022, 17:00) | 18 | 97 % |
