I have X game for Windows which was/will be ported by Y porting house, can I download binaries/installers?
Unless specifically stated otherwise by Y porting house, no. In most cases Y porting house has to pay Z developer for the right to port X game, and most likely royalties for each packaged copy as well. So, by releasing binaries they would be greatly losing money. Especially seeing as how bandwidth, programmers, PR, shelf-space, and looking respectable to the outside world costs lots of cash, this isn’t a viable method.