(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 | |
|---|---|---|---|
 | Fusion by Crusader175 (on 7. October 2022, 17:12) | 15 |  94 % |
| Demolition (Numbered Rooms, Skyscraper) by Crusader175 (on 15. January 2023, 15:00) | 18 | 92 % |
| Guidelines by DarthParadox (on 3. July 2023, 08:11) | 18 | 96 % |
| Islands 3: Another Archipelagic Discovery by SamuPiano (on 21. July 2023, 01:44) | 15 | 100 % |
| Negator XS by thoughtbyte (on 13. September 2023, 00:55) | 67 | 97 % |
| Fillominoku by jsmirob (on 15. December 2023, 02:40) | 20 | 94 % |
| Mady's Moonlander by Abdul the Killer (on 20. February 2024, 12:34) | 64 | 97 % |
| Flansch (Sudoku mit Durchschnittswerten) by glum_hippo (on 30. June 2025, 19:30) | 32 | 94 % |
| Tatamidoku by mathpesto (on 21. June 2023, 04:41) | 91 | 97 % |
| Gravity by jovi_al (on 19. May 2021, 19:16) | 115 | 97 % |
| Ten - Qodec Collab by the_cogito (on 6. May 2022, 19:39) | 43 | 94 % |
| Position Sums (9x9 Chaos Construction) by ONeill (on 18. October 2022, 16:45) | 51 | 100 % |
| Bullet Train by wooferzfg (on 11. April 2023, 05:29) | 47 | 100 % |
| The Quiet Whispers Between Loops by Jolly Rogers (on 30. September 2024, 20:28) | 45 | 94 % |
| Global Entropea by Scojo (on 12. July 2025, 18:26) | 49 | 97 % |
| The clock by NicoD (on 28. July 2025, 05:30) | 47 | 92 % |
| A Symmetry by twototenth (on 1. November 2022, 08:00) | 81 | 98 % |
| Arctic Expedition by Calesch (on 29. June 2024, 21:38) | 72 | 94 % |
| Killer Square Sudoku by ProwlingTiger (on 28. April 2020, 04:38) | 30 | 94 % |
| Ouroboros by zetamath (on 20. April 2021, 03:14) | 64 | 97 % |
