(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 | |
|---|---|---|---|
 | Foundations by Andrewsarchus (on 20. June 2025, 22:13) | 35 |  96 % |
| Sudoku Boogie Woogie by juggler (on 26. November 2025, 11:37) | 40 | 92 % |
| Revenge of Triad by Tyrgannus (on 18. September 2021, 06:57) | 42 | 97 % |
| Bent Glass by arbitrary (on 12. May 2024, 13:00) | 50 | 94 % |
| 5 Years Portal Anniversary by Richard (on 1. November 2013, 12:02) | 95 | 98 % |
| Chameleon [Antiknight Series] by wisty (on 26. November 2024, 15:35) | 71 | 90 % |
| Japanische Summen mit Pentominos by Uhu (on 19. July 2018, 22:22) | 59 | 98 % |
| Masyudoku - Sudoku / Masyu Hybrid by Mr.Menace (on 2. November 2022, 21:14) | 64 | 98 % |
| Candles in the Dark by Dave Sandwich (on 22. November 2022, 23:44) | 71 | 92 % |
| Kreuzzahlrätsel (4) by berni (on 21. October 2010, 11:57) | 42 | 91 % |
| Wichtel 2018 (8): Zahlenweihnachtsbaum by wichtel (on 24. December 2019, 12:08) | 31 | 96 % |
| Adventssterne: Full Rank Star by Realshaggy (on 15. December 2019, 06:00) | 32 | 91 % |
| Renban X-sums sudoku by udukos (on 20. July 2021, 19:45) | 48 | 100 % |
| Median Quads by RockyRoer (on 13. November 2021, 05:07) | 21 | 92 % |
| 真笑Puzzles046--Chaos Construction--ZhangYi005 by cdwg2000 (on 13. March 2022, 00:50) | 21 | 97 % |
| Chaos Construction: Arukone by Dandelo (on 17. April 2022, 01:27) | 23 | 96 % |
| When-in-drome by Mojo872 (on 20. April 2022, 03:41) | 23 | 94 % |
| Regional Variants (ambiguous region sum lines) by AnalyticalNinja (on 4. June 2022, 02:54) | 39 | 97 % |
| Shyscrapers by Lisztes (on 25. July 2022, 23:30) | 30 | 100 % |
| Die Kryptos - S05E02: Teilchenzoo by tuace (on 1. September 2022, 20:22) | 20 | 99 % |
