(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 | |
|---|---|---|---|
 | Noch ein 3D Rundweg by Calavera (on 31. December 2009, 05:49) | 61 |  98 % |
| Thermoconstrictor by HalfBakedLunatic (on 27. October 2023, 19:20) | 61 | 95 % |
| Renban -Kakuro 1-10 / 2 by julius64 (on 4. May 2011, 21:18) | 65 | 94 % |
| Minister of Primes (featured on CtC) by Mountainfarmer (on 6. August 2022, 11:19) | 38 | 94 % |
| Duppels by ICHTUES (on 20. August 2023, 07:21) | 36 | 92 % |
| Ghost Cages by juggler (on 19. July 2024, 03:38) | 77 | 94 % |
| Time to Think Outside the Box by zegres (on 1. March 2022, 06:49) | 52 | 98 % |
| Ménage à Trois by Die Hard (on 5. December 2023, 05:16) | 58 | 95 % |
| Japanische Summen mit Querverweisen by ibag (on 23. December 2011, 21:31) | 70 | 98 % |
| Dense Populations by Mark Sweep (on 5. March 2021, 10:00) | 21 | 97 % |
| Pentominous sandwich sudoku by Nylimb (on 28. April 2021, 17:11) | 19 | 97 % |
| 3D Tapa - Count to Five by athin (on 25. June 2021, 12:00) | 16 | 98 % |
| A + N ∞ (Palindrome + kropki sudoku) by Aspartagcus (on 16. July 2021, 00:02) | 21 | 97 % |
| Balanced Cages by kolot (on 24. September 2021, 16:15) | 23 | 95 % |
| Roadmap by vidarino (on 14. November 2021, 19:21) | 19 | 97 % |
| ew by mathpesto (on 26. June 2022, 18:28) | 62 | 96 % |
| No Black Dots by mormagli (on 7. November 2022, 22:06) | 18 | 100 % |
| Second Region X-Sums Chaos by Elliptical (on 20. November 2022, 21:22) | 40 | 98 % |
| The Magic Potion (Zippular Lines #2) by heliopolix (on 17. December 2023, 02:57) | 38 | 94 % |
| Mysterious Modular Snake by starwarigami (on 10. February 2024, 00:00) | 27 | 94 % |
