It has been a while since I last used Blender, but to my surprise, I found it was rather like riding a bike ... Once you learn how to ride a bike (with training wheels), you never, ever forget !
Here is a screenshot of what I came up with :
Now, before you get (somewhat) excited ... Let me remind you that this is to be a -tiny- 3D game. In fact, I would not even call it a 'game'. I imagine 'interactive picture' would be a more appropriate name for this ...
Basically, the entire 'game' will be inside one of the structures you see in the screenshot. (Inside one room, that is ... )