(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 | |
|---|---|---|---|
 | Anti-Knight Arrow Sudoku by MeloMania! (on 29. October 2020, 16:23) | 18 |  96 % |
| Sudoku Variants Series (323) - Killer Kropki Sudoku by Richard (on 2. June 2021, 00:00) | 61 | 96 % |
| CHRISTBAUM - Buchstabenrätsel / Letter Puzzle by DocLogic (on 20. December 2021, 19:00) | 29 | 94 % |
| Grasshoppers and Horseshoes by antiknight (on 7. March 2022, 23:06) | 15 | 94 % |
| Thin Gloss by mnasti2 (on 30. May 2023, 20:50) | 25 | 93 % |
| Suradewoku (Geradeweg/Sudoku) by Wessel Strijkstra (on 14. July 2023, 01:39) | 16 | 100 % |
| Mönch (Killer sudoku) by Qodec (on 13. December 2023, 21:51) | 68 | 95 % |
| Chackstones (XVXV/Kropki pairs/X-sums) by dumediat (on 27. April 2024, 02:42) | 35 | 92 % |
| Destin Sunset (YIN-Yang Fillomino) by MaizeGator (on 1. August 2024, 15:39) | 31 | 99 % |
| Night on the Galactic Railroad by sfushidahardy (on 19. August 2024, 00:04) | 25 | 96 % |
| Mystery Lines Somedoku by blackjackfitz (on 11. September 2024, 18:29) | 32 | 93 % |
| Turn 1: Parity Yin Yang by yttrio (on 26. October 2024, 02:10) | 33 | 95 % |
| Pentominous Cave by Tacosian (on 8. November 2024, 06:59) | 22 | 94 % |
| Chaos Construction: Double Arrow by Xendari (on 14. November 2023, 02:19) | 77 | 96 % |
| Lazy River (w/ Nordy) by mathpesto (on 8. February 2024, 18:27) | 73 | 96 % |
| Japanese Sums with Arrows by mathpesto (on 31. December 2021, 22:24) | 35 | 94 % |
| Bridges by Xenonetix (on 21. May 2022, 01:35) | 35 | 90 % |
| Capulet [Variant Sudoku] by wisty (on 18. June 2022, 05:36) | 40 | 97 % |
| Microchip by wooferzfg (on 23. July 2022, 02:19) | 38 | 97 % |
| Killer Numbered Rooms by the_cogito (on 21. March 2023, 21:04) | 36 | 94 % |
