If GoG 2.0 is going to be the one-stop-shop, it'd be nice to be able to link an exe installer for games that we might have backed up offline. I know I have a few for games that I own that just are not on any service - small games and the like. It wouldn't be super hard to have an option to link to the installer and then it's a simple matter of GoG simply activating that when you'd like to play the game, especially since you can mark that you own a game without actually linking its exe.

A step further would be to even link the uninstaller as well possibly?