Can you change what resolution "Standalone" is in the Game view?

In the game window there is the pane that lets you select resolutions to view in the editor. Currently I can see, Free Aspect, 5:4, 4:3, 3:2, 16:10, 16:9 and Standalone(1024x768). Is there a way to change what that resolution is that Standalone is?

Go to Edit > Publish Settings > Player and tweek your Default Screen Settings values there.