I found out a non-game breaking bug. If you find yourself at the police station while you confirm the conclusion placed at the bottom right corner of the book (the donations one) the message that pops up won't be the correct one but instead it will be one of the messages from the previous game, the one talking about the adress which isn't the adress of a brain farm.
That said, the game was very clever and this time it wasn't easy as some of the previous ones were since I had to find small details in the game scenery to progress in the game and the hint you got from your assistant was rather vague, just fair, enough to know which place I should have examined better and nothing more.
I also appreciated the treasure hunt you put into this one, it was even sorta thrilling to follow and it wasn't even the entire game because there is much more to do here like the complex final deduction which has multiple "options".
I like the fact that simply combining the evidences isn't enough to properly solve the case, you must also use reasoning and intelligence and keep in mind that things can't be "that easy". This is something I noticed in all of these games, but this one topped them so far in this field.
As a final note, it was nice to see you spent time to come up with jokes that were ultimately "useless" but still were good to read, especially what the clueless old zombies at the retirement castle say when questioned about the evidences you collected. That shows you wanted to create content even if it wasn't useful for the game's main purpose.