The line thickness was my first thought as to what threw me off. Also the lips (more so on the secretary) They seemed fuller and more natural in the pixel art. The vector looked more duck kissy face lol while the pixel looks like lips I'd actual like to kiss. I think those two are my biggest hang up other than probably bias for pixel since that is how it was started lol. I will say I'll still play the game regardless of choice.
Good luck and thanks so much for the effort you are putting into the game!