(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 | |
|---|---|---|---|
 | Thermo Arrow Sudoku by Phistomefel (on 24. May 2021, 04:16) | 96 |  96 % |
| Splatter by PotatoHead21 (on 23. July 2021, 03:35) | 46 | 91 % |
| ripple by mormagli (on 29. November 2022, 22:26) | 86 | 97 % |
| Fujiyama by Myxo (on 14. December 2022, 14:24) | 38 | 99 % |
| Two Truths and a Lie by zetamath (on 20. September 2021, 14:48) | 168 | 98 % |
| Ta(x)i-Cab Sums: by RockyRoer (on 6. December 2020, 13:35) | 28 | 92 % |
| Parity Paradigm by grkles (on 31. December 2021, 13:42) | 26 | 99 % |
| Post Office Panic! by tesseralis (on 4. July 2022, 10:14) | 86 | 98 % |
| Chaos Sum-dok-U-Bahn by Christounet (on 9. December 2024, 08:07) | 28 | 99 % |
| Tenuity (Japanese sums/Pentomino chain) by dumediat (on 14. September 2025, 15:03) | 30 | 100 % |
| Chaotic Archery - Chaos Construction Sudoku by Mr.Menace (on 12. May 2022, 22:51) | 77 | 97 % |
| Red and Blue by zetamath (on 19. February 2021, 18:41) | 46 | 96 % |
| Made to be Broken by jwsinclair (on 23. January 2023, 20:54) | 45 | 96 % |
| Perfectly Average Killers by Tacosian (on 14. March 2023, 03:13) | 44 | 94 % |
| Chaos Sandwich by Bert (on 24. February 2024, 16:36) | 62 | 94 % |
| The Sun by EricRathbun (on 2. June 2024, 00:57) | 62 | 90 % |
| Chromosomes by ThePedallingPianist (on 3. January 2023, 01:15) | 121 | 96 % |
| 真笑Puzzles007:Bachelor(光棍) Sudoku02 by cdwg2000 (on 23. December 2020, 22:43) | 16 | 92 % |
| Stepping Stones by RockyRoer (on 2. October 2021, 15:00) | 31 | 98 % |
| 100 by EricRathbun (on 25. September 2022, 22:50) | 18 | 92 % |
