(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 | |
|---|---|---|---|
 | Vlad the Impaler - Parity mirror, killer sudoku by Mr.Menace (on 19. August 2023, 08:14) | 38 |  94 % |
| Tower of Babel by Jay Dyer (on 6. June 2023, 17:47) | 147 | 97 % |
| Odd Blockade Runners by JeffWajes (on 17. April 2023, 19:44) | 106 | 96 % |
| Japanische Hochhaus-Summen (Mini-Krypto) by ibag (on 21. September 2012, 22:04) | 55 | 98 % |
| Coupled Up by IcyFruit (on 13. February 2024, 17:14) | 65 | 93 % |
| Blast Off (Region Sum Killer Diagonal) by tallcat (on 9. June 2023, 20:18) | 90 | 96 % |
| Sashigane Whispers by yttrio (on 15. March 2024, 19:40) | 112 | 98 % |
| Cave of Killers by Jay Dyer (on 22. April 2024, 23:41) | 115 | 97 % |
| Geburtstagsgruß by ibag (on 20. April 2019, 00:00) | 25 | 90 % |
| Killer Battlefield Sudoku : Enigma by Carrick22 (on 29. May 2020, 12:14) | 37 | 96 % |
| Wärmetod by glum_hippo (on 3. September 2020, 17:55) | 17 | 93 % |
| Wichtel 2019 (9): Hybrid by wichtel (on 4. October 2020, 19:02) | 35 | 99 % |
| Fünfter Pfeilchenstrauß, "Quer Beet" by glum_hippo (on 8. December 2020, 16:37) | 28 | 95 % |
| Yin-Yang Fillomino by Phistomefel (on 7. January 2021, 01:21) | 72 | 98 % |
| Shy Magic Square Sudoku by ICHTUES (on 21. February 2021, 06:00) | 20 | 93 % |
| Ambiguity 2 by zetamath (on 13. April 2021, 02:44) | 44 | 94 % |
| All Crossed Up by Polycarp (on 13. May 2021, 04:45) | 25 | 95 % |
| Killer Wasp by Quarterthru (on 31. May 2021, 12:00) | 29 | 97 % |
| The Fairest in the Land (Inequality Series #6) by twototenth (on 19. October 2021, 08:00) | 18 | 91 % |
| Four Lockout Lines by Lizzy01 (on 30. October 2021, 17:19) | 35 | 98 % |
