(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 | |
|---|---|---|---|
 | Colossal Slitherlink Sudoku by Agent (on 5. September 2023, 09:00) | 43 |  99 % |
| Zum Geburtstag: Das Geschenk by moss (on 5. October 2017, 23:58) | 30 | 99 % |
| Thermal Galaxy Killer by Alexander Rappa (on 11. July 2020, 15:29) | 34 | 96 % |
| Orbit by Qodec (on 16. September 2020, 21:38) | 61 | 100 % |
| Glass Skyscraper Sudoku(P1) by cdwg2000 (on 21. September 2020, 10:20) | 14 | 96 % |
| Chaos Construction: Thermos by XeonRisq (on 8. May 2022, 01:00) | 17 | 98 % |
| Half-Baked by tesseralis (on 24. August 2022, 10:41) | 44 | 97 % |
| Ein Geburtstagsgruß von Wachtel, Wechtel, Wochtel und Wuchtel by ibag (on 27. March 2023, 20:00) | 13 | 98 % |
| Duplication by Xenonetix (on 28. July 2023, 00:00) | 31 | 98 % |
| A Rose by PotatoHead21 (on 2. August 2023, 08:24) | 29 | 94 % |
| The Landmark of Entropia by Mad-Tyas (on 30. March 2024, 09:11) | 31 | 92 % |
| Some Octopus Somedoku by blackjackfitz (on 18. May 2024, 22:51) | 15 | 92 % |
| Chaos Construction: Minesweeper by Phistomefel (on 29. March 2021, 13:28) | 87 | 98 % |
| Blackadder by udukos (on 30. May 2022, 12:14) | 49 | 97 % |
| Zag by grkles (on 18. March 2021, 11:46) | 42 | 98 % |
| Flying Arrows by antiknight (on 2. March 2022, 19:36) | 40 | 91 % |
| Nagaraja [Japanese Sums Cipher Snake Deconstruction] by Christounet (on 12. April 2024, 21:38) | 36 | 98 % |
| Sum Line Sudoku #2 by Phistomefel (on 8. October 2022, 12:57) | 102 | 98 % |
| Japanese Sum Cave Cipher: Fillomino (Parity) by Niverio (on 18. November 2022, 18:32) | 37 | 100 % |
| 247, 368... by twototenth (on 26. September 2023, 08:00) | 20 | 91 % |
