(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 | |
|---|---|---|---|
 | A Quiver of Snakes by The Book Wyrm (on 18. June 2023, 10:07) | 24 |  92 % |
| Badminton (Parity mirror sudoku with arrows and diagonal) by Qodec (on 5. August 2023, 01:12) | 68 | 96 % |
| The 12 Regions of Christmas by IcyFruit (on 15. December 2023, 10:37) | 53 | 96 % |
| Productivity Killer by starwarigami (on 13. January 2024, 21:02) | 24 | 91 % |
| X-Sums & Sandwiches by kolot (on 2. April 2022, 03:02) | 87 | 99 % |
| Falscher Krypto-Rundweg by lupo (on 15. June 2009, 19:24) | 58 | 94 % |
| The Facehugger by sonicbyte (on 12. December 2020, 23:30) | 31 | 97 % |
| Arrow Circus by PotatoHead21 (on 31. May 2023, 23:45) | 31 | 91 % |
| Inner Skyscrapers by tesseralis (on 30. September 2022, 23:08) | 67 | 99 % |
| Normal Lunchboxes 2 by Undar_Beyond (on 25. May 2020, 16:14) | 42 | 92 % |
| For your big heart with lots of room by tenaliraman (on 12. February 2021, 12:45) | 42 | 98 % |
| Parity Balance by zegres (on 12. October 2021, 04:51) | 39 | 95 % |
| Roller Coaster in Rätselhausen by Statistica (on 6. December 2016, 06:06) | 44 | 98 % |
| Chock-a-Block by marty_sears (on 14. May 2024, 01:46) | 50 | 97 % |
| Rundweg auf dem Würfel by flooser (on 3. September 2009, 12:18) | 74 | 96 % |
| Overflow by TotallyNormalCat (on 7. March 2022, 21:00) | 91 | 98 % |
| Loses Kalenderblatt April 2016 by April (on 1. April 2016, 00:00) | 32 | 98 % |
| Für Rollo zum Geburtstag: Speichenrätsel by CHalb (on 23. June 2017, 23:58) | 31 | 95 % |
| Killer Sudoku #1 — ‘The Portal’ by PixelPlucker (on 12. November 2020, 09:48) | 22 | 92 % |
| Club Med (A pure nonconsecutive arrow sudoku) by Farkov (on 9. March 2021, 12:21) | 21 | 95 % |
