Thanks for your answers !
Mainly the game will be divided in two parts. The first part will be the dialogue part where you just follow the story, i didn't think of making any choices here but it can evolve. The second part is the "investigation" part with some mini-games. Here in the video for example it's the first investigation: you have to find the folder of the case that the character lost ! So there you will need to just discover a little trick by opening the drawers to discover where the file is. All of the "investigation" game will be with some point & clicks ideas.
I can give you access to this first part:
password : Mystere
(sorry still in french, my native language :)