(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 | |
|---|---|---|---|
 | The Voice of the Masked Idol who has Got Talent by Morisenseiisgod (on 2. September 2024, 14:01) | 28 |  91 % |
| Mobile Skyscrapers by juddimal (on 22. March 2025, 17:05) | 24 | 95 % |
| What are the sums? by Benji1810 (on 26. March 2025, 20:50) | 26 | 92 % |
| Modular Yin Yang by yttrio (on 17. January 2026, 03:20) | 142 | 96 % |
| Looping Chaos by Paletron (on 12. March 2024, 20:44) | 79 | 95 % |
| Sandwiched Japanese Sums by leftovercube (on 29. December 2021, 21:38) | 25 | 95 % |
| Little Killer Around You by Ridhwan (on 19. November 2023, 03:40) | 27 | 94 % |
| Trading Places by Kafkapharnaum (on 21. January 2024, 04:54) | 28 | 95 % |
| One Challenge Remaining (Flinty & Palpot) by palpot (on 11. July 2024, 13:36) | 31 | 92 % |
| Monster Muddle by Md88keys (on 29. August 2025, 07:04) | 34 | 90 % |
| Modulenburg by RockyRoer (on 14. June 2025, 13:13) | 97 | 95 % |
| Warp Speed by The Bard (on 16. October 2024, 00:02) | 259 | 96 % |
| Sudoku Variants Series (332) - Teleportation Cycle Sums Sudoku by Richard (on 4. August 2021, 00:00) | 82 | 97 % |
| Red Colour by apiyo (on 16. April 2022, 14:02) | 32 | 95 % |
| Doggo Adventure #11 by waffles_the_dog (on 9. February 2023, 10:56) | 35 | 91 % |
| The Sumbin by sanabas (on 22. July 2025, 19:43) | 29 | 90 % |
| Electrostatic Discharge by Allagem (on 14. April 2024, 11:30) | 64 | 93 % |
| Hidden X-Sums & Sandwiches by BL00DW0LF (on 7. August 2020, 05:39) | 32 | 91 % |
| Killer X Sudoku by ICHTUES (on 9. May 2021, 06:00) | 60 | 95 % |
| [New Constraint] Entropy Sudoku by Mad-Tyas (on 3. December 2021, 05:28) | 137 | 93 % |
