(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 | |
|---|---|---|---|
 | Caged Knights Versus The Archers by Jeet Sampat (on 16. May 2023, 18:33) | 38 |  96 % |
| Breakthrough by Xenonetix (on 3. March 2023, 03:03) | 63 | 98 % |
| Confluence by mathpesto (on 24. April 2023, 17:00) | 62 | 98 % |
| Pencil puzzle sudoku hybrid series #5 - Slitherlink killer sudoku by Aspartagcus (on 9. January 2021, 14:48) | 29 | 95 % |
| Wichtel 2020 (7): Ärger in der Wichtelwerkstatt by wichtel (on 15. September 2021, 20:20) | 22 | 100 % |
| Zeta's Nightmare by zetamath (on 15. October 2021, 15:42) | 49 | 97 % |
| Loop with a Coral Infestation by KNT (on 20. August 2023, 20:00) | 24 | 100 % |
| Roundabouts by Black_Doom (on 27. July 2024, 19:36) | 26 | 90 % |
| Old Maid by ICHTUES (on 5. February 2025, 23:34) | 27 | 96 % |
| Zum Geburtstag by Uhu (on 9. July 2017, 00:00) | 39 | 98 % |
| Red and Blue by zetamath (on 19. February 2021, 18:41) | 41 | 96 % |
| Chaos Construction: Slingshots by Piatato (on 26. January 2025, 00:45) | 60 | 97 % |
| Indexed Chaos by Jay Dyer (on 3. September 2022, 23:42) | 70 | 100 % |
| Self-determination by stephane.bura (on 5. September 2022, 15:46) | 76 | 98 % |
| Japanische Summen mit Hochhauskern - gründlich daneben by ibag (on 27. March 2014, 00:00) | 57 | 100 % |
| LM 2016 - Spätfolgen: Sternenhimmel-Japanische Summen by ibag (on 15. August 2016, 20:13) | 42 | 99 % |
| Pentopia Rundweg II by tuace (on 22. April 2019, 09:55) | 50 | 99 % |
| Poison Arrow 2 by FryTheGuy (on 13. May 2021, 04:04) | 17 | 92 % |
| Unbekannte Bahnhöfe by Dandelo (on 13. August 2021, 18:23) | 15 | 100 % |
| Wichtel 2020 (13 und Schluss): Bescherung in Überlappenhausen by wichtel (on 27. October 2021, 20:20) | 14 | 100 % |
