(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 | |
|---|---|---|---|
 | Juosan Killer sudoku by udukos (on 25. October 2021, 05:54) | 47 |  97 % |
| Frankenstein by PotatoHead21 (on 6. November 2021, 13:40) | 29 | 96 % |
| Twinkle Twinkle by starwarigami (on 15. May 2022, 21:18) | 14 | 92 % |
| Balanced Sudoku by Nell Gwyn (on 6. August 2022, 04:03) | 14 | 95 % |
| Lookin' Hot by djorr (on 5. December 2022, 14:00) | 17 | 90 % |
| Fusion by Crusader175 (on 7. October 2022, 17:12) | 15 | 94 % |
| Demolition (Numbered Rooms, Skyscraper) by Crusader175 (on 15. January 2023, 15:00) | 18 | 92 % |
| Guidelines by DarthParadox (on 3. July 2023, 08:11) | 18 | 96 % |
| Islands 3: Another Archipelagic Discovery by SamuPiano (on 21. July 2023, 01:44) | 15 | 100 % |
| Negator XS by thoughtbyte (on 13. September 2023, 00:55) | 67 | 97 % |
| Fillominoku by jsmirob (on 15. December 2023, 02:40) | 20 | 94 % |
| SMOG - Buchstabenrätsel / Letter Puzzle by DocLogic (on 4. May 2024, 13:16) | 29 | 95 % |
| Region Sum Tangram by sfushidahardy (on 7. July 2024, 19:57) | 20 | 94 % |
| Flansch (Sudoku mit Durchschnittswerten) by glum_hippo (on 30. June 2025, 19:30) | 32 | 94 % |
| Tatamidoku by mathpesto (on 21. June 2023, 04:41) | 92 | 97 % |
| Gravity by jovi_al (on 19. May 2021, 19:16) | 115 | 97 % |
| Zippery When Wet by marty_sears (on 20. November 2023, 03:01) | 179 | 99 % |
| Ten - Qodec Collab by the_cogito (on 6. May 2022, 19:39) | 43 | 94 % |
| Bullet Train by wooferzfg (on 11. April 2023, 05:29) | 47 | 100 % |
| Ice Cave by Agent (on 21. November 2023, 09:00) | 44 | 99 % |
