(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 | |
|---|---|---|---|
 | Japanese Slitherlink by KNT (on 27. October 2024, 22:43) | 49 |  97 % |
| Mirror Mirror by Andrewsarchus (on 18. October 2025, 13:58) | 27 | 93 % |
| 2d Wave Particles by zetamath (on 15. July 2021, 18:22) | 32 | 95 % |
| Mean World Syndrome [Mean Arrow, Kropki] by Miky (on 1. May 2023, 17:29) | 36 | 96 % |
| Sandwich Product by Prof.Dori (on 5. July 2024, 09:28) | 36 | 95 % |
| Wichtel 2015 (6): MERRY CHRISTMAS! by wichtel (on 18. May 2016, 20:15) | 41 | 99 % |
| A Wonderful Discovery - Dedicated to Gliperal by damasosos92 (on 21. May 2023, 02:14) | 46 | 97 % |
| Powercut [S-cell, Renban, RSL] by Christounet (on 30. June 2023, 23:48) | 39 | 100 % |
| Motel (Deconstruction: Numbered Rooms) by purpl (on 8. April 2022, 16:42) | 50 | 98 % |
| Snake Sum Sudoku 5 by Quarterthru (on 11. July 2020, 20:00) | 25 | 97 % |
| Where are the cage totals? - Odd/Even killer sudoku (#5) by Mr.Menace (on 2. February 2021, 10:12) | 32 | 95 % |
| The Devil's Arrow by PotatoHead21 (on 6. June 2021, 06:51) | 21 | 92 % |
| Silvester by PulverizingPancake (on 24. January 2022, 02:00) | 40 | 98 % |
| Thonk? by purpl (on 3. May 2022, 00:26) | 28 | 95 % |
| Self-determination by stephane.bura (on 5. September 2022, 15:46) | 82 | 98 % |
| Disambiguation by Flywinged (on 5. February 2023, 01:07) | 22 | 92 % |
| Fillomino Yajilin (10x10) by ns08 (on 8. May 2023, 00:01) | 23 | 95 % |
| Proximity (Renban/Antiknight) by dumediat (on 13. May 2023, 14:29) | 73 | 93 % |
| Schrödinger's Triplers by Oddlyeven (on 22. July 2023, 17:44) | 48 | 99 % |
| [159] Di-Again-y! by ThePedallingPianist (on 11. October 2023, 01:47) | 19 | 90 % |
