(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 | |
|---|---|---|---|
 | hello DubiousMobius by aqjhs (on 5. July 2025, 00:00) | 31 |  97 % |
| Fourteen (Killer Sudoku) by FryTheGuy (on 8. August 2021, 08:13) | 79 | 99 % |
| Killer Turm by tuace (on 17. November 2013, 09:30) | 46 | 98 % |
| Slingshot Fillomino by Jesper (on 15. September 2020, 08:38) | 44 | 99 % |
| Rivers and Islands Fillomino by Jesper (on 19. October 2020, 10:04) | 55 | 98 % |
| Ten-Ban by Niverio (on 13. January 2023, 14:54) | 61 | 97 % |
| The Barbed Cross by SSG (on 30. June 2021, 11:26) | 15 | 92 % |
| Diagonal Spiral by antiknight (on 6. July 2022, 22:35) | 35 | 93 % |
| Japanese Sum Battleship Cipher #1 by wisty (on 8. January 2023, 08:27) | 16 | 100 % |
| Cryptocombination Knapp Daneben by KNT (on 26. March 2023, 15:26) | 29 | 98 % |
| Liar Japanese Sums #6 - Ciphered Tapa by Niverio (on 10. September 2023, 20:47) | 47 | 99 % |
| The 12 Pentominoes of Christmas (Chaos) by DadJokes (on 8. January 2024, 15:19) | 31 | 100 % |
| Arcade (Pentopia + Simple Loop) by sfushidahardy (on 17. November 2024, 01:03) | 35 | 97 % |
| [TSL][S1T2] Adrift, not aimless...Uncertain, not lost (Nurimaze/Taj Mahal) by dumediat (on 22. December 2024, 13:30) | 14 | 96 % |
| [TSL][S1T2] At the Edge of the Future (Variant Foreshadow) by The Book Wyrm (on 14. January 2025, 02:33) | 15 | 98 % |
| Railroaded by someguy209 (on 31. January 2025, 23:33) | 14 | 94 % |
| the arithmancer by aqjhs (on 25. August 2025, 01:36) | 34 | 96 % |
| Checkered Grin (Wraparound, Yin Yang) by DubiousMobius (on 16. September 2025, 22:05) | 17 | 98 % |
| Ten Knights by FryTheGuy (on 20. August 2021, 08:16) | 137 | 97 % |
| Chasm Construction by AFrayedKnot (on 23. May 2024, 22:35) | 122 | 98 % |
