When getting into 'Scooby Doo: Mystery Incorporated' for the first time, "Escape from Mystery Manor" left a big impression on me and was along with "All Fear the Freak" the episode where memories afterwards were particularly vivid. Especially the scene with imprisoned Fred and Daphne and the character of Danny Darrow. All the show's previous episodes were good to excellent, with even the weakest episodes such as "The Wild Brood" having a lot of great things.
"Escape from Mystery Manor" is outstanding in every way. Five or six of the previous episodes were particularly excellent (such as "Howl of the Fright Hound", "The Shrieking Madness" and "Mystery Club State Finals"), but this is the first 'Scooby Doo: Mystery Incorporated' episode to not have anything wrong with it. Not just one of the best episodes of Season 1 but for me also of the whole show, which is one of the few Scooby Doo shows where there isn't an episode below decent.
The animation is beautifully detailed and full of atmosphere, of the genuinely spooky end. Just loved the exteriors and interiors of the house and the creepy character design of Danny Darrow stands out too and quite unique for this stage of the show. The music fits very well tonally, with the right amount of mysteriousness and eeriness which is exactly the right approach for such a mature show like 'Mystery Incorporated'. The theme tune is very spy thriller and haunted house rolled into one and again it's appropriate.
Furthermore, "Escape from Mystery Manor" is one of the best written episodes of the first season. Not just the clever mix of amusing humour, investable drama and intriguing mystery, but also the referencing. The referencing was very clever and affectionate, very adult (with the episode being one big reference to 'Saw', which sounds like a target audience inappropriate disaster on paper but it worked to me) but not too much so that it becomes traumatising for those pre-teenagehood, going into it or in it. Was also familiar with what was being referenced so that aspect was not a problem.
Had no problem getting into the story. There is a lot of genuine suspenseful tension, where there is real worry as to whether the gang would make it out. Loved the heavy emphasis on the Mr E mystery, which advances a lot here and is getting more intriguing all the time. The puzzle piece clue is one of the show's most interesting clues. The ending is one of the show's most unexpected and didn't predict it at all. All the gang are on strong form, Shaggy and Scooby bring a smile to my face and the aforementioned scene with Fred and Daphne brought a lot of depth to their relationship. The voice acting is great, especially for Darrow.
In conclusion, couldn't fault it. 10/10.