Well, after hours of brainstorm and creating the core mechanics, I could say I got the base movement, inventory, user interaction with 3D objects, pickups / collectibles highlighter and files / clue reader working as intended. Need more adjustment before implementing the game level. So here is some of the prototype to test the mechanics (just the bare minimum, with no "asset" yet):

https://www.youtube.com/watch?v=xFuP4EPpOVI