(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 | |
|---|---|---|---|
 | Zodiac Project: Cage Decoder by sujoyku (on 12. June 2024, 23:06) | 113 |  95 % |
| Adventskalender-ABCtje by StefanSch (on 30. November 2012, 00:00) | 34 | 91 % |
| Quad van de Wetering by PotatoHead21 (on 31. March 2024, 23:38) | 107 | 98 % |
| Would you like that toasted? by vitaminz (on 10. July 2024, 03:21) | 39 | 93 % |
| Solo by Kaktuslav (on 23. November 2025, 10:00) | 30 | 98 % |
| Stolen Numerals XV*3 by NurglesGift (on 6. July 2024, 22:12) | 76 | 95 % |
| Sudoku Variants Series (418) - Sum and Product Killer by Richard (on 4. April 2025, 12:00) | 78 | 96 % |
| Anti-sudoku puzzle #3 by Nylimb (on 17. February 2020, 06:56) | 37 | 94 % |
| Little Killer Madness by djorr (on 22. September 2021, 14:00) | 40 | 93 % |
| Sealed Fate by Xendari (on 15. August 2022, 05:55) | 38 | 96 % |
| Twice a night by Fool on Hill (on 10. May 2023, 08:30) | 44 | 92 % |
| MeidjulOOp ! [Meidjuluk N=18; Loop] by Christounet (on 25. October 2023, 21:54) | 40 | 98 % |
| Meidjuizy by Lizzy01 (on 14. November 2023, 11:36) | 42 | 100 % |
| Fair and Square (Equality Cage + Arrow) by Schwupel (on 14. November 2023, 21:58) | 40 | 92 % |
| Doublers Make Me Loop-Pea! by SamuPiano (on 9. September 2024, 15:44) | 38 | 93 % |
| They check in, but they don't check out by Strosahl (on 3. October 2024, 06:13) | 48 | 94 % |
| Cursed Quiver 2 (Region Sum Arrows CC) by Xendari (on 16. December 2022, 08:13) | 52 | 98 % |
| Low Tide by Schwupel (on 18. August 2023, 21:25) | 53 | 91 % |
| Treasury Island by Morisenseiisgod (on 16. May 2025, 18:09) | 53 | 93 % |
| Two-factor by FKlauser (on 6. June 2025, 11:11) | 55 | 98 % |
