(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 | |
|---|---|---|---|
 | Happy Birthday to Naomi by Fool on Hill (on 31. March 2024, 13:51) | 28 |  95 % |
| Sprawling by Xenonetix (on 14. April 2024, 01:01) | 41 | 96 % |
| Chaos Construction: FroZen Pentominoes by oklux (on 25. January 2025, 21:14) | 31 | 96 % |
| Number Snax Doubled by Oddlyeven (on 29. March 2025, 00:51) | 45 | 96 % |
| Yin-Yang Whispers by Scruffamudda (on 4. May 2025, 09:46) | 38 | 93 % |
| Peactograph by NicoD (on 18. September 2025, 05:30) | 39 | 98 % |
| Know Your Rank by Kaktuslav (on 18. October 2025, 08:00) | 33 | 90 % |
| Sandwiched XV Squishmates by SennyK (on 30. December 2025, 23:19) | 23 | 92 % |
| SET Square'd by LeaVulpina (on 9. February 2026, 14:14) | 27 | 95 % |
| Copycat Confusion by Phistomefel (on 19. August 2024, 18:03) | 114 | 95 % |
| Think you can break in? (FOW) by antiknight (on 17. August 2024, 02:06) | 221 | 92 % |
| Sudoku Variants Series (276) - Taxi Ride Sudoku by Richard (on 8. July 2020, 00:00) | 76 | 92 % |
| Crossbow (Arrow variant sudoku) by Qodec (on 10. July 2024, 15:34) | 78 | 94 % |
| Anti-Quads 7 by The Bard (on 1. September 2025, 07:40) | 93 | 95 % |
| The 28th Party (CTC Secret Santa 2021) by Niverio (on 29. December 2021, 00:11) | 76 | 97 % |
| Squares of Parity Sudoku by Richard (on 21. December 2022, 06:00) | 58 | 95 % |
| Sashigane Whispers by yttrio (on 15. March 2024, 19:40) | 120 | 98 % |
| Skyscrapers Sum by abed hawila (on 25. January 2022, 13:00) | 52 | 95 % |
| Kings and/or Knights by Scruffamudda (on 5. August 2022, 03:08) | 50 | 93 % |
| Hidden Sums by jwsinclair (on 27. November 2021, 20:19) | 38 | 97 % |
