(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 | |
|---|---|---|---|
 | Bahamas by Qodec (on 24. April 2021, 20:43) | 112 |  97 % |
| Counting Calories by marty_sears (on 3. June 2024, 07:30) | 120 | 96 % |
| Every Third Knight by JeremyDover (on 4. February 2022, 17:00) | 88 | 94 % |
| Thermo Dot by FullDeck-Missing (on 4. April 2023, 23:54) | 91 | 91 % |
| Odd / Even Killer Sudoku (#1) by Mr.Menace (on 30. October 2020, 21:11) | 24 | 91 % |
| Little Killer by abed hawila (on 18. January 2021, 12:55) | 22 | 94 % |
| Sandwich Thermo Arrow Sudoku by Lizzy01 (on 9. May 2021, 20:17) | 24 | 90 % |
| Ghost Digit by jwsinclair (on 15. October 2021, 19:25) | 27 | 97 % |
| Tic Tac Logic Sudoku by panthchesh (on 12. December 2021, 14:10) | 25 | 94 % |
| HeatTen Up by djorr (on 20. February 2023, 14:00) | 26 | 92 % |
| Odd Cages by Phantou (on 18. July 2023, 22:40) | 44 | 94 % |
| Quantum Chaos (CC, S-Cells) by gdc (on 31. August 2024, 00:26) | 50 | 94 % |
| Pincers (Diagonal constraint killer sudoku) by sujoyku (on 10. September 2023, 09:32) | 96 | 95 % |
| Japanische Summen-Höhle 2358 by Uhu (on 1. August 2017, 22:32) | 48 | 98 % |
| Shrug by zetamath (on 15. December 2022, 16:33) | 111 | 97 % |
| Happy Anniversary Mum & Dad! by ThePedallingPianist (on 26. September 2024, 23:34) | 57 | 96 % |
| Roller Coaster mit Extras 6 by Uhu (on 11. April 2018, 22:43) | 60 | 98 % |
| Even Trios Killer Sudoku by Quarterthru (on 14. September 2020, 12:00) | 33 | 98 % |
| Short THERM 12+1 by Lisztes (on 13. November 2020, 01:00) | 32 | 90 % |
| BLT by zetamath (on 19. June 2021, 20:30) | 31 | 98 % |
