(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 | |
|---|---|---|---|
 | Jam Packed Thick Crust Club Sandwich by sfushidahardy (on 13. February 2025, 00:43) | 36 |  94 % |
| Deep Dive Twenty-Five (Killer sudoku) by sujoyku (on 25. October 2025, 14:09) | 130 | 95 % |
| (Yin)German Pairrows by SennyK (on 6. January 2026, 20:10) | 39 | 92 % |
| Crosshairs by NicoD (on 2. February 2026, 05:30) | 84 | 94 % |
| "Nevermore" ... than Four by XeonRisq (on 13. June 2021, 17:00) | 64 | 94 % |
| Sudoku Variants Series (319) - Star Battle Sandwich by Richard (on 5. May 2021, 00:00) | 96 | 96 % |
| Pointer Arrow Whisper Loop by yttrio (on 14. December 2024, 01:49) | 90 | 98 % |
| Hooked (Region Sum Lines) by Florian Wortmann (on 11. August 2024, 12:24) | 193 | 97 % |
| Killeriana: Ein anderer Psycho-Killer by Pyrrhon (on 2. September 2009, 17:39) | 81 | 93 % |
| BetSandwichween by LKegel (on 10. February 2021, 12:32) | 30 | 92 % |
| Cactus [German Whispers] by Malrog (on 8. January 2023, 01:56) | 35 | 93 % |
| Popcorn by PulverizingPancake (on 6. February 2023, 17:16) | 59 | 93 % |
| Diamonds And Butterflies by Niverio (on 15. July 2023, 17:58) | 58 | 95 % |
| Behaving Loop by ElChiglia (on 11. November 2023, 07:35) | 37 | 99 % |
| Camouflage (Loop Sum Sudoku) by Agent (on 9. July 2024, 09:00) | 27 | 99 % |
| Oil, Water and Soap by ViKingPrime (on 30. July 2024, 00:00) | 26 | 95 % |
| five pointed stars, five lettered cells (Pentominous/Star Battle) by Nell Gwyn (on 18. February 2025, 20:18) | 26 | 100 % |
| Divide and conquer by Lithium-Ion (on 28. March 2026, 11:09) | 23 | 90 % |
| Killeriana: Ungleichungskiller by Pyrrhon (on 8. October 2009, 14:35) | 91 | 96 % |
| Sudoku Variants Series (284) - Isolation Killer Sudoku by Richard (on 2. September 2020, 00:00) | 107 | 96 % |
