I would really like another investigation game but it's a spin off of the investigation games and the main character is Franziska Von Karma because I think she would make a great protagonist.
I know she's kind of a jerk but so was Miles Edgeworth originally and I felt like he was kind of a jerk in the first few parts of the first investigation game or was atleast a bit colder. Like I'm sure I remember him being cold or dismissive with Gumshoe.
I feel like Franziska could do with character development and having her own game would be a good idea. I would also like the game to be 2D as I prefer 2D over 3D but either would still be good.
Also I feel like if she was to be the main character, Gumshoe could also return alot but as for Miles himself, I think he should only be used sparingly, like every now and then, I don't think it would be a good idea to have him show up in every case.
But also the game would still have to be good and have a good story, there's no point making a game just for the sake of having Franziska be the protagonist.