how does it prioritize your game compared to your apps
The old school way would be to use ToS, but it's only effective inside your LAN cuz no one else uses ToS. Application layer throttling on a soho router is highly unlikely - costs BIG bucks in F5/etc gear. There is however open source throttling software - OpenBSD has it installed by default but I don't see how it would happen cuz it would need to be configed and I wouldn't think D-Link, if it were config'd, that it'd be all that finely tuned.
Cool though - been a while since a new feature came to soho routers.