(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 | |
|---|---|---|---|
 | Zeta's Nightmare by zetamath (on 15. October 2021, 15:42) | 46 |  97 % |
| Lawful Wrogn by Niverio (on 20. March 2023, 16:33) | 75 | 95 % |
| Renban Non-con by yttrio (on 21. April 2023, 20:26) | 34 | 95 % |
| Quincies by lerroyy (on 11. June 2023, 19:14) | 35 | 92 % |
| Schrödinger's Triplers by Oddlyeven (on 22. July 2023, 17:44) | 41 | 99 % |
| The Deck of Many Things by ViKingPrime (on 7. September 2023, 20:30) | 11 | 98 % |
| Manhattan by starwarigami (on 10. October 2023, 10:59) | 12 | 95 % |
| Double Killer Sudoku by clover (on 15. December 2023, 21:57) | 29 | 100 % |
| Entropy Antimatter by Mad-Tyas (on 5. March 2024, 16:24) | 35 | 92 % |
| Suguru Chaos Deconstruction #3: Whispering Palindromes by mathpesto (on 20. February 2022, 16:27) | 98 | 97 % |
| Tír na nÓg by Qodec (on 17. July 2022, 10:20) | 57 | 97 % |
| Japanese Nurikabe (1) by KNT (on 4. September 2022, 05:44) | 57 | 99 % |
| Yin Equals Yang by SSG (on 9. September 2022, 07:16) | 53 | 95 % |
| Thorny Tie (Killer Deconstruction) by Agent (on 12. July 2022, 09:00) | 42 | 99 % |
| Killer Quads by RockyRoer (on 19. September 2022, 03:14) | 43 | 100 % |
| Araf Killer Sudoku by Phistomefel (on 28. July 2020, 09:00) | 86 | 98 % |
| Whispering Knight by Phistomefel (on 22. October 2021, 01:13) | 125 | 95 % |
| Faultline (Filloku #4) by mormagli (on 12. October 2023, 20:15) | 29 | 100 % |
| Chaos Construction by Phistomefel (on 21. April 2020, 00:27) | 133 | 97 % |
| Thermal Equilibrium (Chaos Construction) by Agent (on 19. July 2022, 09:00) | 91 | 100 % |
