Why call this a browser game?
Its not like your going to be using flash or something... From the looks of it your using IE and an Active X control to launch the game... Which when its all said and done, doesn't really make it browser based at all...
My company does something like this, we have an 130mg install for a browser based application, crazy...
I really hope I'm wrong here because that would surely limit anything else other that MS and IE....