New [C:\bmx\regaa/littleShooter.bmx;49;1]

BlitzMax clearly doesn't like it if you use "New" in a field definition. It's those "New"s that are causing the problem, not the "New" you have commented. I don't know why this is, but I'm sure someone will be along in a minute to explain. Anyway, change the beginning of Spiel to this:

Type Spiel
	Field Bild:Screen
	Field Bg:Starfield

	Method Init()
		Bild = New Screen
		Bild.Create()
		Bg = New Starfield
	End Method
    ...