Games are the only thing you can't run with good performance inside a VM. That's why you can always spin up a Windows VM if you need Photoshop but you HAVE to reboot if you want to enjoy a game. So yes, this would be definitely a game changer
I've had luck with VMWare and nvidia cards, as long as your processor supports virtulization. Near-native performance, minus the fact that you have Linux eating some of your resources. It gets pretty touchy though, and last time I tried it on an ATI card the drivers didn't support it.
