Mechanical and electronics side of it is the easy part. What I would see being a problem is getting the game to talk your similator. If its anything like CNC you need to turn the movement of the game into G code. A further program(loads of these available from free to megabucks) to read the G code and translate into motor/ram movement.
G code and the processing program are standard fare. But getting the software companies to embed the G code in the various games is the hard part.
What price bracket are you looking at for this simulator? I spent £1500 just building a basic 3 axis CNC made of MDF(precision parts linear slides bumped price) and a further £1000 on programs.
What are you thinking to use for movement? Steppers, Servos or rams?