use blitzmaxGUI for game launcher?

Is it any slower to use a single canvas for a game with no gui elements?

if it is slower, how do you launch a game after choosing resolution with a small gui app

Probably not.

Create a separate program that lets the user choose a resolution, then when you run the game just pass the resolution as an argument to the game.

why have separate apps? you know you can mix the two.

SuperStrict 

Import MaxGUI.drivers

Local window:TGadget = CreateWindow("My Window",40,40,320,240)

Global screenWidth:Int
Global screenHeight:Int

While Not screenWidth And Not screenHeight
   WaitEvent 
   Print CurrentEvent.ToString()
   Select EventID()
   	Case EVENT_WINDOWCLOSE
   		screenWidth = 640
		screenHeight = 480
		FreeGadget window
   End Select
Wend

Graphics screenWidth,screenHeight

While Not KeyHit(KEY_ESCAPE)
	Cls
	If AppTerminate() Then End

	DrawText "blitz graphics",10,10

	Flip 1	
Wend