(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 | |
|---|---|---|---|
 | Projectile Perturbation by DadJokes (on 24. August 2022, 19:34) | 86 |  96 % |
| LM 2016 - Leftover: Yajilin by lupo (on 15. July 2016, 20:16) | 66 | 93 % |
| Killer Sudoku - Progress City by DiMono (on 14. September 2020, 01:27) | 65 | 97 % |
| Campfire by Nahileon (on 12. January 2022, 21:24) | 52 | 97 % |
| Stuck In The Middle With You (Between Broken 159) by tallcat (on 15. January 2022, 00:11) | 48 | 98 % |
| Archery Zone by Ridhwan (on 3. June 2023, 18:16) | 59 | 97 % |
| Krypto-Kongruenz-Rundweg (2) by ibag (on 6. September 2009, 18:31) | 45 | 94 % |
| Parity Sum Lines Sudoku by Agent (on 16. August 2022, 09:00) | 48 | 97 % |
| Prismatic Palindromes by Scojo (on 19. November 2024, 01:10) | 105 | 97 % |
| Killer Sudoku - Ignorant of 9's by ProwlingTiger (on 10. May 2020, 00:49) | 44 | 94 % |
| Chaotic Sandwiches (Entropy Special) by Mad-Tyas (on 2. January 2022, 21:29) | 41 | 96 % |
| Transfer by Emphyrio (on 15. March 2022, 03:06) | 42 | 96 % |
| Concordia (Sum dots, X-Sums, Kropki, German Whisper) by Bellsita (on 7. February 2025, 21:49) | 44 | 97 % |
| Kakuro-Koralle by ibag (on 5. September 2013, 23:55) | 75 | 96 % |
| Erster Pfeilchenstrauß by glum_hippo (on 16. August 2020, 09:33) | 44 | 95 % |
| Region X-Sums by twototenth (on 4. October 2022, 08:00) | 38 | 92 % |
| Whisper Loop-de-Loop by yttrio (on 25. May 2023, 17:57) | 79 | 98 % |
| Modular Mid-Loop by yttrio (on 5. October 2024, 01:48) | 34 | 94 % |
| Ping Pong by antiknight (on 19. January 2025, 19:37) | 81 | 94 % |
| SAT Sudoku (Quads and Anti-Quads) by RockyRoer (on 27. August 2021, 13:00) | 77 | 97 % |
