(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 | |
|---|---|---|---|
 | X---V*Lines by NurglesGift (on 4. October 2025, 18:47) | 32 |  94 % |
| Ultramarathon by oklux (on 24. November 2025, 17:37) | 15 | 93 % |
| Modular Full Rank by phil_the (on 27. April 2026, 23:15) | 27 | 94 % |
| Japanische Summen PQR by tuace (on 4. November 2016, 15:30) | 51 | 98 % |
| Fishie by zetamath (on 7. September 2021, 01:33) | 58 | 94 % |
| Border Square Diagonals by Phistomefel (on 21. May 2024, 19:16) | 110 | 97 % |
| Line of Sight Chaos Production (9x9) by RockyRoer (on 4. February 2022, 03:10) | 40 | 99 % |
| The "Sum of Sums" Puzzle (that no one asked for) by Jeet Sampat (on 24. January 2023, 17:35) | 35 | 99 % |
| A Quiver of Snakes by The Book Wyrm (on 18. June 2023, 10:07) | 31 | 93 % |
| Schrödinger 303: S-Duality by ViKingPrime (on 9. September 2024, 17:30) | 33 | 91 % |
| Overlooked by IcyFruit (on 7. November 2025, 12:21) | 98 | 97 % |
| Foggy Banren by DarthParadox (on 9. August 2024, 23:18) | 91 | 94 % |
| Japanische Summen mit 50 by ibag (on 7. September 2018, 08:50) | 61 | 98 % |
| Bullseye Sudoku by RockyRoer (on 29. July 2020, 21:59) | 54 | 96 % |
| Eternal Life by Sktx (on 20. May 2021, 12:35) | 23 | 99 % |
| O vs. X by ICHTUES (on 4. July 2021, 06:00) | 23 | 92 % |
| Lucky Arrows by PotatoHead21 (on 9. August 2022, 22:28) | 29 | 92 % |
| Double fillomino by filuta (on 8. December 2022, 15:38) | 24 | 99 % |
| Arrow Replica Addition by PotatoHead21 (on 30. April 2023, 17:34) | 24 | 90 % |
| Opposition (Black holes/Killer/Teleporting little killer) by dumediat (on 9. February 2024, 12:00) | 22 | 99 % |
