Erynar: Why would you need a 64-bit version? 32-bit applications run just fine on 64-bit Windows, and given what it does, if GoG Galaxy is using enough memory for it to need to be a 64-bit application, then it's doing something seriously wrong. Presumably, GoG just made it 32-bit, because it wouldn't actually benefit from being a 64-bit application, and if it's 32-bit, then they don't have to worry about having a separate version for the people running 32-bit Windows.
zoulnix: Switching from 32 to 64 is not just about memory usage (more than 4GB). Moving an app to 64-bit will improve both performance and security. The security benefits are nice, although i don't think you will notice that much of an difference on the performance side for an app like this; maybe just a slight improvement :P
Steam runs both 32 and 64; i do however think that the main client is 32-bit.
Whether it improves performance or not is very application-dependent, and I have no clue why you would think that it would improve security. As a programmer, I do wish that we could just move everything to 64-bit and kill off 32-bit, since having to worry about both can be annoying, and there are plenty of applications where the limits of 32-bit addressing make life harder, but I don't see why GoG would benefit particularly from GoG Galaxy being a 64-bit application. The games themselves can be 32-bit or 64-bit regardless of what the client is. Heck, the installer for a game could even be 32-bit when the game itself is 64-bit (or vice versa, though that seems kind of pointless).
