(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 | |
|---|---|---|---|
 | Japanische Hochhaus-Summen (Mini-Krypto) by ibag (on 21. September 2012, 22:04) | 54 |  98 % |
| 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) | 34 | 99 % |
| Fünfter Pfeilchenstrauß, "Quer Beet" by glum_hippo (on 8. December 2020, 16:37) | 27 | 95 % |
| Shy Magic Square Sudoku by ICHTUES (on 21. February 2021, 06:00) | 20 | 93 % |
| 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 % |
| Quatre Coins: Four Corners 2 (Kropki Arrow X) by tallcat (on 11. July 2021, 14:51) | 65 | 95 % |
| 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 % |
| Whispering Skyscrapers by Florian Wortmann (on 9. January 2022, 13:22) | 37 | 92 % |
| Coriolis (Lockout X)(Tallcat and Twototenth Collab) by tallcat (on 30. January 2022, 20:56) | 37 | 95 % |
| Fifth Amendment (Killer Diagonal Sudoku) by Agent (on 4. March 2022, 09:00) | 33 | 96 % |
| Integral Magic Squares by mathpesto (on 16. April 2022, 18:32) | 16 | 93 % |
| Chaos Construction: Renbans by XeonRisq (on 11. August 2022, 05:00) | 51 | 94 % |
| Guillotine by Qodec (on 4. September 2022, 12:20) | 49 | 94 % |
| Companions by Joseph nehme (on 3. November 2022, 09:46) | 17 | 91 % |
| Sequence Boxes by Cane_Puzzles (on 1. January 2023, 07:48) | 36 | 93 % |
