test.scad contents:
$vpr = [55, 0, 360*$t];
sphere(20);

Powershell Console Output:
> C:\Program` Files\openSCAD\openscad.com -o test.png --imgsize="640,480" --view=scales --projection=o --animate 36 --preview test.scad
Exporting test.scad...
WARNING: Viewall and autocenter disabled in favor of $vp*
Compiling design (CSG Products normalization)...
Normalized CSG tree has 1 elements
Geometries in cache: 1
Geometry cache size in bytes: 62072
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Total rendering time: 0:00:00.259
Exporting test.scad...
Compiling design (CSG Products normalization)...
Normalized CSG tree has 1 elements
MS GDI - RegisterClass failed
last-error code: 1410
Can't create OpenGL OffscreenView. Code: -1.
Geometries in cache: 1
Geometry cache size in bytes: 62072
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Total rendering time: 0:00:00.000