Ok, I 100%'ed it in about 7 hours. I'm not normally the type to clean up all the achievements and collectables, but after finishing the game in 5 hours, I saw I was already close enough to finish the game. There were a few little extra puzzles in there to get the last few cards/invitations, and I did really like the reward.
Overall the game is really charming. I think the thought put into the sound design should deserves particular praise. In fact, I recommend to incoming gamers to turn DOWN the sound effects and turn UP the music, because the music actually does a lot of the heavy lifting in regards to tone, atmosphere, and story telling.
The other highlight for me was the mansion itself. By the end of the game I had memorized most of its winding passageways, even despite its tremendous amount of doors. This speaks to how well the visual design of this game was, making even bare hallways discernable from one another. In a game where time keeping can be critical, being able to know exactly where I was in the large estate without having to keep referring to my map was a big timesaver, and a great success of the game overall.
Storywise, I was impressed in how much it tried to turn an off the wall concept into a coherent plot, although I'm not entirely sure they completely nailed it. There are still a few questions regarding the plot that don't seem to hold up to scrutiny.
Gameplaywise, I was happy with what we got. I just wanted MORE. A more reactive sandbox. More failure states. More intricacy. More puzzles. This game reminded me a whole lot of the Wii game Zack and Wiki, another niche and cute puzzler that just didn't throw enough at the player before the credits rolled.
As far as a proof of concept, I think The Sexy Brutale is strong, but I feel like a sequel would allow Tequila Works to really nail the ideas explored here. Unfortunately, the amount of discussion I've found online seems to suggest that this game wasn't too much of a success, so I have my doubts as to whether or not we'll be revisitng this Ghost Trick-esque gameplay soon.