(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 | |
|---|---|---|---|
 | Position Sums mit Renban-Streifen by glum_hippo (on 29. June 2021, 07:23) | 33 |  97 % |
| Building Blocks by grkles (on 2. February 2022, 04:00) | 34 | 97 % |
| All Directions by Joseph nehme (on 19. February 2022, 07:48) | 34 | 97 % |
| U-Bahn with Fillomino enclosures #3 (12x12) by Jesper (on 10. November 2024, 13:37) | 33 | 96 % |
| Ediacarium (Still Life Sudoku) by Qodec (on 12. October 2025, 18:37) | 37 | 95 % |
| Unique Values by Mesmer (on 25. January 2021, 12:20) | 75 | 98 % |
| Chaos Construction: X-Sums / Sandwich by KNT (on 13. April 2022, 17:12) | 66 | 94 % |
| Negatively Constrained Slingshot Sudoku by stephane.bura (on 6. August 2020, 20:00) | 34 | 94 % |
| Half Full Jar by Nimo (on 25. February 2025, 10:47) | 34 | 95 % |
| How to Slice a Sandwich by ul-Rhymm (on 18. March 2026, 16:48) | 34 | 93 % |
| Deconstruction Chaos Suguru #1,729: It’s All a Lie! by mathpesto (on 2. April 2022, 20:58) | 128 | 99 % |
| Half Life (Yin Yang Deconstruction) by Agent (on 30. August 2022, 09:00) | 85 | 99 % |
| X---V*4 by NurglesGift (on 11. April 2025, 06:00) | 98 | 96 % |
| DIY Arrows by sophmayrob (on 15. June 2023, 07:59) | 55 | 98 % |
| Loop with a Coral Infestation by KNT (on 20. August 2023, 20:00) | 29 | 96 % |
| 440 Hz by HalfBakedLunatic (on 19. March 2024, 02:38) | 28 | 92 % |
| Liar Japanese Sums #9 - Cave (Aqre) by Niverio (on 1. August 2024, 19:24) | 29 | 100 % |
| Pentomino Schleifen (NFF) by Richard (on 8. October 2010, 12:00) | 28 | 92 % |
| Millstone by jwsinclair (on 13. June 2024, 20:59) | 81 | 98 % |
| Rising Arrow Sudoku - Halloween Crab by DiMono (on 3. June 2021, 18:26) | 54 | 97 % |
