(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 | |
|---|---|---|---|
 | Akari Sudoku by Prasanna16391 (on 30. July 2020, 00:05) | 18 |  90 % |
| Rounded Killer Sudoku by RockyRoer (on 7. January 2021, 00:00) | 18 | 90 % |
| Maggot Sandwich by Piatato (on 8. August 2022, 11:07) | 33 | 97 % |
| Quarrowdruples by Joseph nehme (on 19. August 2022, 17:32) | 26 | 90 % |
| Shady Combination #2: Country Road, Heyawake, LITS, Yin Yang by Myxo (on 24. January 2023, 16:12) | 36 | 97 % |
| Arrow Spine Indexing by Die Hard (on 20. March 2023, 11:58) | 19 | 95 % |
| Liar Sum Before Digit 9 #1 by Playmaker6174 (on 2. April 2023, 13:07) | 17 | 93 % |
| Star Killer Part 3: Lunch Break by FischmitFahrrad (on 5. January 2024, 20:00) | 19 | 97 % |
| 200 Streams of Zetatude (Modifiers, Renban, Region Sum, Arrows, Anti-consecutive) by Chilly (on 28. December 2023, 14:25) | 17 | 93 % |
| World's Tallest Sandwich by Jreg (on 21. August 2024, 13:01) | 19 | 91 % |
| Clean Sweep [Parity Sweepers, Quads, Difference Dots collab with Mathgeek] by Malrog (on 7. November 2024, 17:06) | 16 | 92 % |
| Summation U-Bahn (Knapp-daneben) by goodcity (on 25. August 2025, 15:36) | 18 | 100 % |
| The Crown of Lucifer by Donatello_86 (on 6. January 2026, 01:48) | 17 | 97 % |
| Heat Ladder by Rab3aron (on 26. February 2026, 12:32) | 32 | 93 % |
| Knapp daneben-Tapa by flooser (on 10. June 2009, 12:32) | 92 | 96 % |
| Constantinople by jwsinclair (on 4. February 2026, 21:13) | 59 | 97 % |
| 24 Rätsel in 24 Stunden (Teil 16) - Koralle by Zzzyxas (on 24. June 2017, 15:24) | 80 | 93 % |
| ¿? Mystery products ¿? by Qodec (on 28. August 2020, 16:32) | 25 | 97 % |
| Thermo Arrow Sudoku by clover (on 15. October 2020, 00:54) | 20 | 97 % |
| Chaos Construction: Equality by SSG (on 27. February 2022, 07:08) | 18 | 97 % |
