(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 | |
|---|---|---|---|
 | Entropy Killer by Mad-Tyas (on 8. December 2021, 00:59) | 99 |  97 % |
| Quadruple Knights Out of Order by GBPack (on 23. July 2023, 17:20) | 125 | 94 % |
| Two Face [Arrow Renban GW Sudoku] by Christounet (on 29. December 2025, 23:19) | 62 | 97 % |
| Jetzt gehts rund, Takashi by tuace (on 6. July 2014, 10:30) | 48 | 99 % |
| Quali 2017 - Leftover: U-Bahn by ibag (on 29. January 2017, 20:17) | 52 | 98 % |
| Odd Tapasyu by usp (on 29. October 2014, 00:00) | 46 | 98 % |
| All the Arrows, Big and Small by bboom (on 24. October 2024, 10:06) | 52 | 95 % |
| Arrow or Centipede? by EricRathbun (on 11. September 2022, 18:08) | 46 | 99 % |
| Chaotic Evil by mathpesto (on 29. April 2022, 00:00) | 135 | 98 % |
| Manta by IcyFruit (on 1. May 2025, 14:01) | 105 | 97 % |
| Killer Thermo Sudoku by tsc (on 12. February 2021, 21:12) | 32 | 90 % |
| 25 by ICHTUES (on 26. February 2021, 12:26) | 34 | 98 % |
| Hustle and Bustle by taylorsc (on 11. May 2022, 02:23) | 27 | 95 % |
| K⁴NQ⁴ by DarthParadox (on 11. November 2022, 08:24) | 35 | 90 % |
| Square Dancing by EricRathbun (on 1. October 2024, 10:16) | 30 | 91 % |
| Zippular Region Sums by gdc (on 27. March 2024, 19:00) | 28 | 97 % |
| Region Sum and Renban lines by psninn (on 27. September 2024, 20:29) | 70 | 90 % |
| A BAD IDEA by PrimeWeasel (on 31. January 2021, 12:10) | 18 | 97 % |
| The Knot by tenaliraman (on 9. April 2021, 00:46) | 43 | 94 % |
| Disjoint 258 Sudoku by Qodec (on 8. October 2021, 18:05) | 62 | 94 % |
