(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 | |
|---|---|---|---|
 | Castle Wall/Cave #2 by MagnusJosefsson (on 28. May 2021, 10:02) | 34 |  98 % |
| Advanced Kinematics (Projected Sum Arrow) by tallcat (on 6. April 2022, 20:08) | 38 | 90 % |
| Perforate by Xendari (on 14. July 2022, 08:22) | 38 | 98 % |
| Counting Circles in Circles by egubachu (on 16. April 2025, 04:43) | 39 | 94 % |
| Quem Dixere Chaos by mathpesto (on 9. February 2022, 05:06) | 59 | 96 % |
| Entropical Pairadise (Pairrow, Yin Yang) by DubiousMobius (on 23. January 2025, 16:44) | 62 | 99 % |
| Squares and Circles by Burning Curtains (on 15. August 2021, 20:17) | 43 | 98 % |
| Despair by XeonRisq (on 3. March 2024, 21:00) | 21 | 97 % |
| Some Kind of Chaos by marty_sears (on 24. May 2024, 09:25) | 139 | 98 % |
| Sunflower by RockyRoer (on 22. September 2021, 19:20) | 58 | 96 % |
| Confined Sandwich Chaos by PrimeWeasel (on 6. July 2022, 16:55) | 55 | 97 % |
| Never (Yajilin/Sudoku) by Wessel Strijkstra (on 6. November 2022, 17:41) | 52 | 95 % |
| Meidjuluk Fillomino Permaculture by Agent (on 27. June 2023, 09:00) | 86 | 96 % |
| Fillomino Sudoku by spxtr (on 29. August 2020, 08:26) | 30 | 95 % |
| 真笑Puzzles023--N-Sums Sudoku--Counter by cdwg2000 (on 5. February 2021, 17:45) | 30 | 100 % |
| Palindromaze by FinnishGuy (on 14. September 2021, 20:25) | 31 | 90 % |
| Remanence by Emphyrio (on 12. October 2021, 04:24) | 36 | 97 % |
| Killer Kropki Cages sequel by Ryx (on 28. March 2023, 06:45) | 33 | 91 % |
| Slythering [Liar Japanese Sums Snake] by Christounet (on 4. June 2024, 07:54) | 30 | 100 % |
| Mictēcacihuātl (Castle Wall Delta + Directed U-Bahn) by sfushidahardy (on 22. May 2025, 08:11) | 28 | 95 % |
