You can set the resolution of your application by calling Screen.SetResolution which is documented here:

http://unity3d.com/support/documentation/ScriptReference/Screen.SetResolution.html

If you add this to a scripts start function and attach it to the Main Camera this will force the application to display full screen at a given resolution.

Void OnGUI() { GUI.matrix = Matrix4x4.TRS(Vector3.zero, Quaternion.identity, new Vector3(1.0f * Screen.width / 1024, 1.0f * Screen.height / 768, 1)); . . . . }