(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 | |
|---|---|---|---|
 | Jet Lag (Renban Killer Sudoku) by Agent (on 29. April 2022, 09:00) | 30 |  96 % |
| 30-1=29 by EricRathbun (on 15. January 2023, 01:58) | 25 | 96 % |
| Japanese Sums Cave Cipher: Nonogram Cave-ception by Xendari (on 8. January 2023, 13:59) | 30 | 99 % |
| Nemesis by igniteice (on 3. January 2024, 15:54) | 47 | 92 % |
| Stolen Numerals XV*V by NurglesGift (on 9. August 2024, 20:17) | 77 | 91 % |
| Mystery of Osaka by .proxz14 (on 13. March 2025, 11:45) | 29 | 98 % |
| It's a Wonderful Day For Pi! by SirWoezel (on 14. March 2025, 00:00) | 24 | 92 % |
| [PAC] Castle Wall (Knapp-Daneben) by The Book Wyrm (on 14. September 2025, 23:41) | 23 | 97 % |
| Four By Four by IcyFruit (on 29. February 2024, 17:13) | 65 | 94 % |
| Quaere (Kropki + Counting Quads) by tallcat (on 26. June 2024, 23:37) | 58 | 97 % |
| Archer's Heart by SudokuExplorer (on 5. October 2021, 00:00) | 48 | 98 % |
| Wichtel 2020 (10): Vier Wichtel, vier Viertel by wichtel (on 5. October 2021, 02:02) | 27 | 99 % |
| Spiral Fillodoku (Spiral Galaxy, Fillomino, Killer sudoku hybrid) by AnalyticalNinja (on 29. March 2023, 21:25) | 60 | 98 % |
| Tapa mit Steigerung by berni (on 5. February 2009, 15:07) | 178 | 95 % |
| Quadstruction by Oddlyeven (on 7. May 2023, 21:25) | 65 | 98 % |
| Rundweg mit gespaltener Persönlichkeit by Calavera (on 1. July 2009, 16:23) | 88 | 99 % |
| Stitch the Broken Ring by LuckyNumber8 (on 13. April 2021, 01:43) | 20 | 93 % |
| Meta-Icing by Kafkapharnaum (on 11. July 2023, 01:24) | 17 | 100 % |
| Galactic Aquariums (Spiral Galaxy Aquarium hybrid) by AnalyticalNinja (on 17. August 2023, 01:04) | 19 | 97 % |
| Modular Snakes by Prof.Dori (on 27. October 2023, 09:20) | 40 | 100 % |
