(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 | |
|---|---|---|---|
 | Sudoku Variants Series (332) - Teleportation Cycle Sums Sudoku by Richard (on 4. August 2021, 00:00) | 75 |  97 % |
| Wrogn Answers Only by jwsinclair (on 19. October 2022, 19:44) | 196 | 98 % |
| Bäume im Herbst: Mini-Höhle by r45 (on 7. November 2019, 20:00) | 38 | 98 % |
| Little Killer Thermo Palindrome Sudoku by Cane_Puzzles (on 19. March 2021, 16:16) | 43 | 95 % |
| Circles and Adders by Jay Dyer (on 24. December 2023, 12:04) | 38 | 95 % |
| Cross The Streams by Uhu (on 3. August 2024, 21:19) | 37 | 96 % |
| Monstertruck Logical by AnnaTh (on 7. June 2010, 16:21) | 40 | 90 % |
| Under Pressure (Pressurized Aquariums) by AnalyticalNinja (on 22. December 2022, 15:00) | 95 | 98 % |
| Parity Party II - "Little Killer at Summer Camp" by glum_hippo (on 11. April 2020, 20:54) | 46 | 92 % |
| Odd Couples Killer Sudoku by Quarterthru (on 29. August 2020, 12:00) | 45 | 95 % |
| Cryptic Star Nurikabe by BenceJoful (on 24. September 2021, 09:19) | 45 | 100 % |
| Pointing Down by Visumation (on 22. October 2024, 11:56) | 46 | 91 % |
| Speed Up by ademjaz (on 6. October 2022, 11:04) | 48 | 96 % |
| Doppelganger: Crypto Japanese Cave by KNT (on 1. April 2023, 04:05) | 45 | 100 % |
| Chaos Construction: Gaps by KNT (on 29. March 2022, 07:47) | 103 | 93 % |
| Alien X-Sums Sudoku by Realshaggy (on 11. November 2022, 12:15) | 54 | 92 % |
| LM 2023 Überbleibsel - Japanische Summen, schwierigere Version by Zzzyxas (on 8. July 2023, 20:23) | 55 | 97 % |
| Skyscraper, Arrow, and Killer by old thousand (on 3. October 2022, 04:30) | 59 | 92 % |
| Elephants & Castles by juggler (on 1. July 2024, 12:50) | 59 | 97 % |
| Wingnuts by FullDeck-Missing (on 7. September 2024, 13:09) | 63 | 92 % |
