(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 | |
|---|---|---|---|
 | Rivers and Islands Fillomino by Jesper (on 19. October 2020, 10:04) | 55 |  98 % |
| Ten-Ban by Niverio (on 13. January 2023, 14:54) | 60 | 97 % |
| Doubler Chaos (Chaos Construction) by Mad-Tyas (on 19. November 2024, 23:39) | 133 | 96 % |
| The Barbed Cross by SSG (on 30. June 2021, 11:26) | 14 | 92 % |
| Diagonal Spiral by antiknight (on 6. July 2022, 22:35) | 34 | 93 % |
| 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 % |
| [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) | 16 | 98 % |
| Ten Knights by FryTheGuy (on 20. August 2021, 08:16) | 136 | 97 % |
| Matroschka, grosse Version by pirx (on 5. February 2016, 18:00) | 45 | 97 % |
| Little Killer Arrow Sudoku by Phistomefel (on 2. March 2021, 11:50) | 74 | 97 % |
| Tapa / Islands / Narrow Cave Permaculture by KNT (on 3. July 2024, 02:40) | 36 | 96 % |
| only love can save us by aqjhs (on 15. September 2025, 21:21) | 34 | 99 % |
| Chaos Construction: Exclusions by KNT (on 1. May 2024, 18:08) | 135 | 92 % |
| Quadratum by Xenonetix (on 23. July 2022, 22:22) | 52 | 99 % |
| Chasm Construction by AFrayedKnot (on 23. May 2024, 22:35) | 121 | 98 % |
